Program and Book of€¦ · COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015 SCIENTIFIC PROGRAM 5 27th of May 2015 08:30 - 09:00 Registration and Reimbursement Forms collection. 09:00

COST ACTION FP1105. Understanding wood cell wall structure, biopolymer interaction and composition: implications for current products and new materials

Scientific Program and Book of Abstracts May 25‐27, 2015 San Sebastian, Basque Country, Spain

INDEX Scientific Program 1 Abstracts 5 Key note presentations 5 Presentations 11 Poster presentations 31 Author Index 70

COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015 SCIENTIFIC PROGRAM

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COST Action FP1105: Agenda for San Sebastian Meeting 25th of May 2015 17:00 - 19:00 Registration and participation fee payment 26th of May 2015 08:30 - 09:00 Registration and participation fee payment (attendance list signature). 09:00 - 09:30 Welcome and Introduction to the workshop by the Action chair, Philip Turner 09:30 - 10:00 Presentation from the hosts: Luis Serrano and María González: General information Dr. Jalel Labidi: Biorefinery processes group, Polytechnic School of San Sebastian, University of the Basque Country 10:00 - 12:00 4 Presentations (20mins + 10mins) Session chair: Pasi Kallio 10:00 - 10:30 Argyropoulos, Dimitris: Correlations of the Antioxidant Properties of Softwood Kraft Lignin Fractions with the Thermal Stability of its Blends with Polyethylene. 10:30 - 11:00 Pesquet, Edouard: Wood post-mortem lignin formation. 11:00 - 11:30 Tejado, Alvaro: Hydrophobization Of Cellulose Fibres: The Ultimate Strategy. 11:30 - 12:00 Gravitis, Janis: Is The Biosynthesis Of Lignins Controlled By Genes Or Physico-Chemical Factors? Lignins Self-Assembled Fractal Cluster Structures. Overview 12:00 - 12:15 Coffee Break


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12:15 - 13:45 Poster presentations (5 mins) Session chair: Tomas Larsson Podkoscielna, Beata: Polymeric Sorbents Manufactured By Synthysis Of Lignin Acrylates With Styrene And Divinylbenzene. Czubak, Ewelina: Towards Improvement Of Self-Assembled Functionalized Lignocellulosic Composite By Cellulose Microfiber Layer. Morais, Danila: Isolation And Characterization Of Acetylated Xylan From Sugarcane Bagasse. Dinesh, Fernando: Understanding Internal Fiber Development During Tmp Refining Of Sulphite Pretreated Spruce Chips. Dizhbite, Tatiana: Revealing Of Lignin Structure-Antioxidant Activity Relationship Using Analytical Pyrolysis And Chemometry. Hocaoğlu, Güliz: Cationic And Anionic Nanofibrillated Celluloses For Papermaking. Bock, Henry: Solvents for Cellulose: Insight from Computer Simulation. Lange, Heiko: Determination Of Molecular Weights Of Lignins: Accuracy And Precision Aspects. Raschip, Irina: Structural Evaluation Of Materials Based On Xanthan Gum And Lignin. Preis, Itan: Modifications of Cell Wall Properties by Production of Recombinant Resilin Composites in Transgenic Plants. Syverud, Kristin: Composite Hydrogels With Cellulose Nanofibrils. Alma, Hakki: Preparation Of Activated Carbon Fibers From Phenolated Biomass Wastes. Sobiesiak, Magdalena: Control of protein affinity in bioactive nanocellulose by passivation with engineered PDMAEMA-block-POEGMA copolymers and false positive responses. Vuoriluoto, Maija: Control of protein affinity in bioactive nanocellulose by passivation with engineered PDMAEMA-block-POEGMA copolymers and false positive responses. Popescu, Maria: Structure evaluation of composite materials based on CNC. 13:45 - 14:45 Buffet lunch


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14:45 - 15:35 Poster presentations (5 mins) Session chair: Geoffrey Daniel Huskic, Miro: Grafting Of Policaprolactone Onto Nanocellulose Obtained By Liquefaction. Niinivaara, Elina: Flexibility Of Cellulose Nanocrystal Networks In Response To Water Vapor. Gordobil, Ohiana: Evaluation Of Softwood Kraft And Organosolv Lignin As Feedstock For Biofuels And Biomaterials. Gianni, Paola: Lipoxygenase For Oxidatively Derivatising Lignins. Ferreira, Paulo: Cnf In Papermaking: Influence On The Wet-Web Resistance And Handsheets Properties Using Pcc As Filler. Giner, Rafael: White Water Recirculation In Handsheet Forming As A Means To Evaluate Fines Properties. Prado, Raquel: Changes On Lignin Structure Influenced By The Ionic Liquid. Salminen, Reeta: Cellulose Submonolayers. Ondaral, Sedat: Polyelectrolyte Complex And Layer By Layer Technique Of Starches. Salan, Tufan: Liquefaction Of Wood And Its Application For The Production Of Thermosetting Molding Materials. 15:35 - 16:00 Coffee Break 16:00 - 17:20 4 Presentations (15mins + 5mins) Session chair: Claudia Crestini Popescu, Carmen: Thermal Properties Of Different Hardwood Species. Kutzke, Hartmut: Curing Wood With Wood: Wood Components As Consolidation Materials For The Conservation Of Archaeological Wood. Filpponen, Ilari: Carboxymethyl Cellulose Assisted Redispersion Of Dried Nanocellulose Substrates. Guo, Jiaqi: Carbon Dots (Cds) Modified Cellulose Nanocrystals (CNC) For Bio-Imaging. 17:20 - 18:30 Poster session & drinks 20:00 Dinner


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27th of May 2015 08:30 - 09:00 Registration and Reimbursement Forms collection. 09:00 - 10:00 Management Committee meeting 10:00 - 12:00 Working Groups meetings Session chair: Working group chairs 12:00 - 13:00 Open discussion 13:00 - 14:00 Lunch 14:00 - 15:40 5 Presentations (15mins + 5mins) Session chair: Jalel Labidi Trifol, Jon: Hybrid Nanocellulose/Clay Composites For Controlled Release. Jajcinovic, Marina: Determining the breaking load of individual fiber - fiber joints by means of different testing devices. Rojas, Orlando: Valorisation Of Residual Biomass: A Conscious But Also Technical Proposition. Peresin, Soledad: Local Thermal Characterization Of Nanocellulose Films Coated With Inorganic Thin Films, Deposited By Atomic Layer Deposition. Benjamin, Wilson: Cellulose-Inorganic Hybrid Films With Thermoelectric Properties. 15:40 - 16:00 Coffee Break 16:00 - 17:20 4 Presentations (15mins + 5mins) Session chair: Philip Turner Bartzoka, Elisavet: Polyphenols Based Microcapsules By Ultrasonic Irradiation. Zikeli, Florian: Wheat Straw Lignin - Successive Fractionation And Structural Characterisation. Orelma, Hannes: Affibody Functionalized Bacterial Cellulose Tubes For Biofiltration Applications. Chabbert, Brigitte: Ectopic Lignification In The Flax Lignified Bast Fiber Mutant 17:20 - 17:30 Goodbye from the Chair 17:30 End of workshop

ABSTRACTS

Keynote presentations

COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015 Keynote presentations

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CORRELATIONS OF THE ANTIOXIDANT PROPERTIES OF SOFTWOOD

KRAFT LIGNIN FRACTIONS WITH THE THERMAL STABILITY OF ITS BLENDS WITH POLYETHYLENE

DIMITRIS S. ARGYROPOULOSa, b*, HASAN SADEGHIFARb

aDepartments of Chemistry & Forest Biomaterials, Organic Chemistry of Wood Components Laboratory,

North Carolina State University bKing Abdulaziz University, p.o. box 80203, Jeddah 21589, Saudi Arabia

Center of Excellence for Advanced Materials Research (CEAMR) *E-mail: [email protected]

ABSTRACT

Since technical lignins are increasingly considered as additives to polyolefins, an effort has been made to understand fundamental antioxidant properties of softwood kraft lignin and its fractions on the thermal stability of its blends with polyethylene. Lower molecular weight acetone soluble kraft lignin (ASKL) fractions showed better antioxidant properties than unfractionated and acetone insoluble kraft lignin (AIKL). By selectively methylating the phenolic hydroxyl groups of the lignin and its fractions it was shown that the lignin had no antioxidant ability. The phenolic OH groups in lignin, therefore, play a vital role toward imparting antioxidant characteristics in it. To further understand the role of lignin during the thermal processing of polyethylene, we measured the Oxidation Induction Temperature (OITtemp) of its blends with softwood kraft lignin and its fractions. Once again, the role of the phenolic OH was found to be extremely important towards the thermal oxidative characteristics of kraft lignin and its fractions. Since acetone soluble softwood kraft lignin contains 54% more phenolic units than its acetone insoluble counterpart, its blends (5 wt. %) with polyethylene improved its OITtemp by about 50 °C with no additional increases at higher lignin contents. At elevated processing temperatures when polyethylene blends of lignin start to degrade, the aromatic nature of the created char reduces its rate of degradation, concomitantly increasing the thermal degradation temperature of polyethylene. This effect was further investigated and details of the relative contributions of the phenolic OH stabilization mechanism to the charring mechanism will be discussed.


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WOOD POST-MORTEM LIGNIN FORMATION

DELPHINE MÉNARD, HENRIK SERK, EMIKO MUROZUKA AND EDOUARD PESQUET Department of Plant Physiology, Umeå Plant Science Centre (UPSC), Umeå, Sweden

[email protected]

ABSTRACT Lignification and programmed cell death (PCD) are of fundamental importance to the production of functional wood vascular cells which require PCD to hollow out their content and lignification to reinforce their wall to transport sap (Ménard and Pesquet, 2015). The interplay between PCD and lignification during TE formation was studied at the cellular level using in vitro xylogenic cultures, at the genomic level using differential subtractive libraries and at the whole plant level by analyzing the cell wall biochemistry of 51 Arabidopsis KO mutants in newly identified genes differentially responding to TE PCD inhibition. Pharmacological modulation of TE lignin monomer biosynthesis resulted in dead unlignified TEs, which could partially lignify post-mortem when supplied externally with lignin monomers. Pharmacological modulation of TE PCD in the differentiating TEs blocked both cell death and lignification without affecting xylan/cellulose secondary wall deposition. Interestingly, cinnamoyl-CoA reductase (CCR) and cinnamyl alcohol deshydrogenase (CAD), two lignin monomer synthesis genes, were expressed beyond normal TE lifespan. In situ localization using IS-RT-PCR of CAD and CCR revealed that both genes were expressed in cells analogous to xylem parenchyma. Cell wall composition analysis of 51 Arabidopsis mutants in genes differentially responding to TE PCD inhibition were characterized by reverse genetic approaches and exhibited changes in lignin composition in whole plants although gene expressions were restricted to xylem parenchyma (Pesquet et al., 2013 and Serk et al., 2015). Altogether, our results suggest that lignin in wood vascular cells is through a post-mortem and cooperative process with xylem parenchyma.

REFERENCES [1] Ménard D. and Pesquet E. (2015) Cellular interactions during tracheary elements formation and function. Current Opinion in Plant Biology, 23, 109-115. [2] Pesquet E, Zhang B, Gorzsás A, Puhakainen T, Serk H, Escamez S, Barbier O, Gerber L, Courtois-Moreau C, Alatalo E, Paulin L, Kangasjärvi J, Sundberg B, Goffner D, and Tuominen H (2013) Non-cell autonomous post-mortem lignification of tracheary elements in Zinnia elegans. Plant Cell, 25, 1314-28. [3] Serk H, Gorzsás A, Tuominen H and Pesquet E. (2015) Cooperative lignification of xylem vessels. Plant Signaling & Behavior, in press.


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HYDROPHOBIZATION OF CELLULOSE FIBRES: THE ULTIMATE STRATEGY

ALVARO TEJADOa, THEO VAN DE VENb

aTecnalia Research & Innovation, Área Anardi 5, 20730 Azpeitia (Spain) b Mcgill University, 3420 University St., Montreal (Canada)

ABSTRACT

From the most basic to the most advanced use, cellulose seems always to be one step ahead of any other material, be it natural or synthetic. Besides being the most abundant biopolymer on earth, as well as being renewable, biodegradable and carbonneutral, cellulose shows a combination of unique properties which make it a very valuable raw material. In the building of a new sustainable world, resource-efficiency must be a fundamental concept and, in that direction, promoting the use of cellulose fibres, as opposed to their dissolution via chemical or physical intensive treatments, not only makes sense for economic and ecologic reasons but should be a priority in order to get the most of the vast potential of such highly-engineered structures. One example is the presence of a hollow interior (lumen), which directly provides effective insulation and reduced density but also opens the possibility to use fibres as compartments to carry other substances. From the point of view of advanced materials, cellulose hydrophilic character is the major responsible for most of its limitations, especially for its limited use in polymeric formulations. Accordingly, intensive research has been done in the last decades to change or at least minimize such characteristic but most attempts have failed to provide durable hydrophobicity. Based on the combination of old knowledge and recent findings, a new highly efficient approach for cellulose hydrophobization has been developed (Tejado et al., 2014), which for the first time results in totally hydrophobic and durable cellulose fibres. Such innovation, based on (i) preventing hornification and (ii) carrying out a surface polymerization via a gas-phase reaction, gives rise to some radically novel products exhibiting spectacular properties, such as a paper with negative hygro-expansion coefficient (expands upon drying) (Chen et al. 2015). This presentation describes in detail and discusses this new methodology as well as the physical phenomena related to it.


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Figure 1: Hydrophobized cellulose fibres in contact with a drop of water.

REFERENCES

[1] Chen, W.C., Tejado A., Alam, M.N. and van de Ven, T.G.M. (2015). Hydrophobic cellulose: a material that expands upon drying, Cellulose in press. [2] Tejado, A., Alam, N., Chen, W.C. and van de Ven, T.G.M. (2014). Superhydrophobic foam-like cellulose made of fully hydrophobized cellulose fibres, Cellulose 21, 1735- 1743


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IS THE BIOSYNTHESIS OF LIGNINS CONTROLLED BY GENES OR PHYSICO-CHEMICAL FACTORS? LIGNINS SELF-ASSEMBLED

FRACTAL CLUSTER STRUCTURES. Overview

JANIS GRAVITIS Latvian State Institute of Wood Chemistry, dzerbenes st. 27, Riga lv1006, Latvia

[email protected]

ABSTRACT Interpretation of lignin biosynthesis Recently we can recognize two contradictory and sometimes aggressive to each other viewpoints of lignin biosynthesis interpretation.The first one (Davin and Lewis1989) is based on idea that lignin biosynthesis is the same as proteins, polysaccharides, DNA/RNA formed by condensations, thermodynamically driven by coupled dephosphorylations of nucleotide triphosphates and catalyzed by proteins giving strictly gene controlled chemical structure. That interpretation emphasize role in regio- and stereoselective monolignol radical-radical coupling is catalyzed by the dirigent (in Latin dirigere to guide or align) proteins (DiP). The second one (Ralph 2005) interprets that at least lignin and suberin are formed by oxidative coupling, where the monomers are oxidized into resonance stabilized radicals, which couple by uncatalize In lignin biosynthesis interpretation d radical-radical reactions. Such coupling is followed by nucleophilic reactions on quinone methide intermediates. The DiPs are probably not involved in the lignin biosynthesis, since they only produce optically active products. Lignins are completely racemic polymers. In a -ether 110-mer, there are actually only 218 optical centers, and therefore 2117 physically distinct isomers – an astronomicall large number. This is lignin random assembly combinatorial biochemistry approach. Natural lignin could be produced by slow end-wise type polymerization. The data obtained by Riga group confirm this concept. Scaling and lignin fractals I would like to explain the essence of the present report by a picture from the book “Scaling Concept in Polymer Physics” by the Nobel Prize winner De Gennes (Fig. 1).

Figure 1: Illustration of scaling idea according de Gennes.

If specific details are ignored a wide class of systems shows simple universality features at different scale levels. The scaling hypothesis is closely connected with the universality hypothesis. Under the same limiting conditions, various physical systems fall in the same universality class. Universality classes are characterized by a set of scaling constants (indexes). Fractal dimension Df is the most important index. In


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Mandelbrot’s fractal geometry the fractal or Hausdorff-Besicovitch dimension Df reflect the space-filling ability of lignin fragments.

Recalculation of fractal dimension (Df) was done from scaling indexes of lignin fragments hydrodynamic properties according to (Kokorevics et al.1989):

from intrinsic viscosity: [] ~ Ma Df = 3 / ( a + 1 ) ,

from diffusion coefficient: D ~ M-b Df = 1 / b ,

from sedimentation constancy: S ~ Mc Df = 1 / ( 1 - c )

from g’ factor: g’ ~ Md Df = 3 / ( d + 3/2 ) ,

where: M - mass parameter or parameter proportional to mass (degree of polymerization). The values of Df have been obtained from 1.70 to 2.70. Hence, scaling indexes highlight the pathway for understanding lignin technological transformations.We can conclude, that according to our approach, the wood secondary wall S2 layers lignin is a network of connected polydisperse fractal clusters.

Lignin nanometre particle study using laboratory small X-ray scattering and synchrotron radiation The cell wall nanoscale structure (compact or fractal) is an important for the properties of wood and tree stability. In opposite to cellulose lignin cluster nano structure is not fully understood in each detail. The first question is experimental characterization of lignin nanometer structures. Small-angle X-ray scattering at laboratory and synchrotron sources provide an excellent tool to study lignin nanometer structures in solid and dissolved form. The data obtained by USAXS and SAXS (Vainio, Serima., Gravitis 2006) for kraft lignin demonstrates Fig.2.

a) b)

Figure 2: a) The intensity of 5 g/l solution of Kraft lignin (0.1 M NaCl ionic strength, pH 7): USAXS (dots) and SAXS (circles). The gyration radius Rg of the lignin particles is 2.3 nm. b)

The calculated distance distribution function for the average lignin particle as a function of R (solid line) and for the simulated platelet (dotted line). The bead models of the lignin and the platelet in the inset are not in relative scale.

REFERENCES

[1] Kokorevics A., Gravitis J., Ozol'-Kalnin V. (1989). The Development of the Investigation of the Supermolecular Structure of Lignin From the Scaling Viewpoint. Lignin as a Fractal (Review) Khimiya Drevesiny (Wood Chemistry). No. 1, 3-24 (http://www.kki.lv/dokumenti/Lignins_Fractals_Review_1979.pdf).

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Presentations

COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015 Presentations

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THERMAL PROPERTIES OF DIFFERENT HARDWOOD SPECIES

CARMEN-MIHAELA POPESCU, MARIA-CRISTINA POPESCU Petru Poni Institute of Macromolecular Chemistry, Iasi, Romania

[email protected]

ABSTRACT The characterization of wood structure is a complex procedure involving several steps wherein wood components are isolated or degraded to monomeric fragments. Thermal analyses are capable to provide accurate information on the phase transition and degradation temperatures, kinetics of various processes, etc. mainly if thermogravimetry/differential thermogravimetry is used together with infrared spectroscopy and two dimensional correlation spectroscopy. The later one (wavenumber-wavenumber 2D IR correlation spectroscopy) of heated samples is very sensitive to the small structural variations and provide information on molecular arrangements, phase transitions and the interaction between wood components. It was observed that different wood species exhibit different characteristics in the same experimental conditions of analysis. This can be observed from not only one mode of analysis. The variation of the integral absorptions of the FT-IR bands, analysis of band ratios, which reflect relative shifts in chemical wood composition, revealed site-specific features. The ratio values of lignin/carbohydrate IR bands for wood decreases with increasing the average specific gravity. The shape of DTG curves depends on the wood species that cause the enlargement of the peaks or the maxima of the decomposition step varies at larger or smaller temperatures ranges. The temperatures and global kinetic parameters are particular for each kind of wood.


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CURING WOOD WITH WOOD: WOOD COMPONENTS AS CONSOLIDATION MATERIALS FOR THE CONSERVATION OF

ARCHAEOLOGICAL WOOD

HARTMUT KUTZKEa, EMILY MCHALEa, CAITLIN MCQUEENa, MIKKEL CHRISTENSENa and TORE BENNECHEb

a Museum of Cultural History, University of Oslo b Department of Chemistry, University of Oslo

[email protected]

ABSTRACT

During the last decades, the use of biopolymers in various fields has significantly increased. How can the conservation of cultural heritage objects benefit from this development? The present contribution will focus on the potential use of wood components like lignin or cellulose and their derivatives as conservation materials for archaeological wood, exemplified by the Oseberg find. The Oseberg find In 1904, a Viking age gravemound, situated at the Oseberg farm 100 km southwest of Oslo, was excavated. Beside an almost complete Viking ship a lot of grave goods were found: metal objects, textiles, bones, and many wooden artifacts, daily-life objects as well as richly ornamented ceremonial objects (Fig. 1).

Fig. 1: Ceremonial wagon from the Oseberg find After excavation a big part of the wooden objects were treated with alum salt in order to support the wooden structure and to conserve the arifacts. Unfortunately, this treatment initiated a deterioration of the wood which is still giong on. Today the objects are in an alarming condition (Fig. 2).


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Fig. 2: X-ray microtomography of alum-conserved wood.

Reasons for the decay are an extremely high acidity (pH 0-2) and the presence of various metal ions. An ideal conservation material should consolidate the wood structure, control the pH value and inactivate the metal ions, for example by chelating reactions. Moreover, the production and handling of the material is without any risk for health and environment . The use of biopolymers opens the door to a new generation of conservation materials. These materials combine the advantages of “Green Chemistry” with thecapacity to form complex networks with tailor-made functionalities. To achieve the desired properties, bio-polymers may be combined with inorganic components, forming hybrid or composite materials with a hierarchical order. This presentation will mainly focus on research performed in the Saving Oseberg group in Oslo, but will also touch on results reported by other groups and give an overview of the fast-growing field of new bio-inspired materials for conservation of archaeological wood.


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CARBOXYMETHYL CELLULOSE ASSISTED REDISPERSION OF DRIED NANOCELLULOSE SUBSTRATES

ILARI FILPPONEN, ANU ANTTILA, ORLANDO J. ROJAS

Department of Forest Products Technology, School of Chemical Technology, Aalto University, p.o. box 16300, 00076 Aalto, Finland

[email protected]

ABSTRACT The possibility to redisperse dried cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs) would facilitate the transportation and storage of such materials.1 In this work, carboxymethyl cellulose (CMC) was adsorbed onto birch pulp in prior to its mechanical disintegration to corresponding CNF. This procedure was not only found to promote the disintegration of the fibrils but also to facilitate the redispersion of the dried CNF.2 Different amounts of CMC in relation to the original pulp (w/w) were employed to screen the optimal dosage. Moreover, the adsorption of CMC onto CNCs (from HCl hydrolysis) was found to improve their redispersion after drying. The morphologies of as produced CNFs and CNCs were characterized by atomic force microscopy (AFM). The amount of adsorbed CMC was measured by titrimetric methods and its effects to the redispersability of nanocellulose substrates will be discussed.

REFERENCES [1] Butchosa, N. and Zhou, Q. (2014). Water redispersible cellulose nanofibrils

adsorbed with carboxymethyl cellulose. Cellulose, 21, 4349–4358. [2] Junka, K., Filpponen, I., Johansson, L.-S., Kontturi, E., Rojas O.J. Laine, J.

(2014). A method for heterogeneous modification of nanofibrillar cellulose in aqueous media. Carbohydrate Polymers, 100, 107-115.


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CARBON DOTS (CDS) MODIFIED CELLULOSE NANOCRYSTALS (CNC) FOR BIO-IMAGING

JIAQI GUOa, ILARI FILPPONENa AND ORLANDO J. ROJASa,b

aDepartment of Forest Products Technology, School of Chemical Technology, Aalto University, 00076 Espoo, Finland

bDepartment of Forest Biomaterials, North Carolina State University, Raleigh, NC 27695, USA [email protected]

ABSTRACT

TEMPO-oxidized cellulose nanocrystals (TO-CNC) were modified by covalent EDC/NHS coupling of luminescent, water-dispersible carbon dots (CDs) (Junka et al. 2014). The prominent properties of CDs include stable photoluminescence, hypotoxicity and excellent biocompatibility which are desirable features for example in bioimaging applications (Liu et al. 2011). Quartz crystal microgravimetry with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR) were used to investigate the attachment of CDs on TO-CNC. Moreover, atomic force microscopy (AFM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were applied to characterize the main morphological features of the produced bio-hybrid materials. Bio-imaging application based on synthesized CDs modified TO-CNC will be studied.

Figure 1: AFM image of TO-CNC (a) and Luminescent carbon dots (b)

Scale bar: (a) 200nm and (b) 100 nm

REFERENCES [1] Junka, K., Guo, J., Filpponen, I., Laine, J. and Rojas, J.O. (2014). Modification of cellulose nanofibrils with luminescent carbon dots. Biomacromolecules, 15 (3), 876–881 [2] Liu, C., Zhang, P., Tian, F., Li, W., Li, F. and Liu, W. (2011). One-step synthesis of surface passivated carbon nanodots by microwave assisted pyrolysis for enhanced multicolor photoluminescence and bioimaging. Journal of Materials Chemistry, 21, 13163-13167.


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HYBRID NANOCELLULOSE/CLAY COMPOSITES FOR CONTROLLED RELEASE

J. TRIFOLa*, A. GARCIAb, C. SILLARDb, O. HASSAGERa,

A. E. DAUGAARDa, J. BRASb, P. SZABOa

aDanish Polymer Centre, Department of Chemical and Biochemical Engineering, Søltofts Plads, Building 227, DK – 2800, Kgs. Lyngby, Denmark

bLGP2/Grenoble INP-Pagora/CNRS, 461 rue de la papelerie, Domaine universitaire, C10065, 38402 Saint Martin d’Hères Cedex, France

*[email protected]

ABSTRACT In previous works nanocellulose and nanoclay were compared as nanofillers for PLA based nanocomposites both individually both together. The combination of nanoclay and nanocellulose had a synergetic behaviour on terms of crystallization kinetic and thermomechanical and barrier properties. The hybrid PLA/CNF/C30B 5%-5% showed a 90% of decrease on the Oxygen Transmission Rate and a 74% on the Water Vapour Transmission Rate respect neat PLA. A deeper study on the water vapour barrier properties of PLA based nanocomposites showed that a) the degree of crystallinity is not the only relevant parameter in the barrier properties of the nanocomposites, since different crystalline structures have different effects on the mass transport across the PLA films and b) the presence of nanofillers with the PLA matrix decreased the mass transfer through the film by reducing the diffusion of water. A nanocomposite with a reduced diffusion is interesting not only for the improvement on the barrier properties but also is interesting for active packaging applications since a smaller diffusivity will lead to a slower release of active compounds through the matrix. Moreover in order to decrease even more the release of active compounds, benzyl acetic acid (BzAA) was grafted to the surface of the CNF. As long as the BzAA is an absorbent which has been used to improve the aroma barrier properties, it seems a promising candidate to decrease the release of the active compound. In this work the performance of hybrid composites as active packaging was evaluated using MeOH 95% as food simulant and carvacrol as active compound. Finally the performance of the carvacrol as plasticizer agent for PLA was evaluated.


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DETERMINING THE BREAKING LOAD OF INDIVIDUAL FIBER - FIBER JOINTS BY MEANS OF DIFFERENT TESTING DEVICES

MARINA JAJCINOVICa, POOYA SAKETIb, WOLFGANG JOHANN FISCHERa,

WOLFGANG BAUERa, PASI KALLIOb aGraz University of Technology

bTampere University of Technology [email protected]

ABSTRACT

To get a better understanding of fibre – fibre joint properties and the influence that sample handling has on it, two different testing devices were used to determine the breaking load of individual fibre –fibre joints. A comparison has been made between the results obtained with the device developed by Fischer et al. 2012 (manual handling), and device developed by Saketi and Kallio 2011a and b (automated handling). Furthermore, the influence of modes of loading on breaking load of individual joints has also been investigated.

INTRODUCTION

The strength of paper mainly depends on the strength of individual fibres and fibre-fibre joints (Page 1969). Dealing with manual handling there is always a possibility of weakening or breaking a joint prior to testing, resulting in only strongest joints being tested. Therefore, two approaches have been used for the determination of the breaking load of individual fibre - fibre joints. An approach using the microbond tester (Fischer et al. 2012) developed at Graz University of Technology (TUG) and an approach using the microrobotic platform (Saketi and Kallio 2011a) developed at Tampere University of Technology (TUT). The main difference between these two methods is the handling of the joints. In the first case the samples are being handled manually whereas in the latter case, the joints are being handled using microgrippers. Both devices have the ability of performing tests under three different modes of loading – Mode I (peeling mode), Mode II (shearing mode) and Mode III (torsional loading). Detailed description of the modes of loading is given in Magnusson et al. (2013). Another point of interest is the determination of the microfibril angle (MFA) using the microscopic transmission ellipsometry. Convenience of this method is that it is non-destructive, therefore enabling subsequent tensile tests and joint strength measurements.

MATERIALS AND METHODS All tests have been performed using an unbleached softwood kraft pulp (mixture of spruce and pine) which was unbeaten and once dried. The fibres had a mean width of 32 μm and the length of 2.13 mm (length weighted average).


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In the method developed at TUG the individual fibre - fibre joints are manually placed onto the sample holders and glued using nail polish. After positioning on the microbond tester the bridges connecting the upper and lower part of the sample holder are melted and load is applied via a linear table until breaking occurs. Detailed description of preparation and testing procedures are given in Kappel et al. (2009) and Fischer et. al (2012). In the method developed at TUT, individual fibre – fibre joints are placed on a rotary “joint storage”. Afterwards, the joint is gripped using three microgrippers (moveable in X, Y and Z direction) and the load is applied via one of the grippers until breaking occurs. Detailed description preparation and testing procedures used at TUT are given in Saketi and Kallio 2011a and b. Determination of MFA has been performed using microscopic transmission ellipsometry. Fibre-fibre joints are manually placed onto a glass slide and the measurements are performed using two different wavelengths of light and four different azimuths between the polarisers. The relative retardation of the fibre walls has the same value as the fibril angle but with opposite sign. Eight images of every fibre have been taken and reference points have been marked and measured. Detailed description is given in Ye et al. (1997) and Hirvonen et al. (2014).

RESULTS AND DISCUSSION

Joint strength measurements For the Mode I joint strength measurements, a setup described in Saketi and Kallio, (2011a) was used. Testing was conducted on overall 14 joints. The results of these tests are shown in Figure 1a. The mean joint strength is 1.61 mN (median 1.40 mN). A possible outlier has been initially included in the results, but later on removed after a Dixon outlier test according to DIN 53804 indicated an outlier significant on a 95% confidence level. For the Mode II joint strength measurements, the setups described in Fischer et al (2012) and Saketi and Kallio (2011b) were applied. The mean value of 14 tests conducted at TUG is 6.58 mN (median 4.56 mN) and the mean value of 5 joint strength measurements conducted at TUT (Saketi and Kallio 2011b) is 4.97 mN (median 2.34 mN). The results of these tests are shown in Figure 1b.

Figure 1. Results of joint strength measurements

Microfibril angle measurements The results of the measurements are not reported, as they show a large variance which could be attributed to differences in the polarising properties, fibre defects, influence of S1- and S3-layer, fibre shrinkage or other changes in the S2-layer. To verify the


19

validity of the results, the samples were covered with glass slides and stored for future measurements using alternative methods.

SUMMARY Joint strength measurements of softwood pulp fibres have been performed using two different testing devices and two different modes of loading (Mode I and Mode II). The breaking loads obtained in Mode I are 71% smaller than those obtained in Mode II loading which shows the significance of the loading mode on the joint strength. Since the measurements of the MFA show great variance further tests are needed. Results of the measurements will be verified using a different method such as X-Ray diffraction, beam-line or light microscopy.

ACKNOWLEDGMENTS Financial support for this work in the framework of the PhD School DokIn’Holz funded by the Austrian Federal ministry of Science, Research and Economy, Sappi and Mondi is gratefully acknowledged. The authors also want to acknowledge COST Action FP1105 for financial support to conduct this Short Term Scientific Mission to Tampere University of Technology, Finland.

REFERENCES [1] Fischer, W.J., Hirn, U., Bauer, W. and Schennach, R. (2012): Testing of individual fiber-fiber joints under biaxial load and simultaneous analysis of deformation, Nord. Pulp Paper Res. J., 27(2), 237-244. [2] Hirvonen, J., Latifi, S.K., Palovuori, K. and Kallio, P. (2014): Semi-Automatic Measurement of Microfibril Angle on a Microrobotic Platform. Proceedings of the Fourth International Conference on Manipulation, Manufacturing and Measurement on the Nanoscale (3M-NANO), Taipei, Taiwan [3] Kappel, L., Hirn, U., Bauer, W. and Schennach, R. (2009): A novel method for the determination of bonded area of individual fiber-fiber bonds, Nord. Pulp Paper Res. J., 24(2), 199-205. [4] Magnusson, M.S., Zhang, X. and Östlund, S. (2013). Experimental Evaluation of the Interfibre Joint Strength of Papermaking Fibres in Terms of Manufacturing and in Two Different Loading Directions. Exp. Mech., 53(9): 1621-1634. Page, D.H. (1969). A Theory for the Tensile Strength of Paper. Tappi J., 52(4):674-681. [5] Saketi P. and Kallio P. (2011a): Microrobotic platform for making, manipulating and breaking individual paper fiber bonds, ISAM 2011 International Symposium on Assembly and Manufacturing, Tampere, Finland [6] Saketi, P. and Kallio, P. (2011b): Measuring Bond Strength of Individual Paper Fibers Using Microrobotics, Hirn, U. (ed.), Progress in Paper Physics Seminar, Graz, Austria.


20

VALORISATION OF RESIDUAL BIOMASS: A CONSCIOUS BUT ALSO TECHNICAL PROPOSITION

ORLANDO J. ROJAS

Department of Forest Products Technology, School of Chemical Technology, Aalto University, 00076 Espoo, Finland

[email protected]

ABSTRACT In this talk I will introduce our efforts to obtain high-value materials from different biomass resources, including Empty Palm Fruit Bunch Fibers (EPFBF), beetle-killed pine, high lignin-content residual fibers, coir fibers from coconut husk (all considered highly-constructed precursors) and, at lower construction levels, lignin, chitosan and proteins. In the case of fibers, the limitations of some of their assemblies are removed, for example, high microfibrillar angles, making the production of nanocelluloses quite attractive for the purpose of developing strong materials. On the other hand, the presence of lignin, usually considered as a drawback, can actually be utilized to design materials possessing expanded property spaces. Thus, we will demonstrate the use of renewable forest and agricultural resources to obtain materials with exceptional performance, and examples will be given, including films, composites and nonwovens. Related efforts take advantage of the multiple-scale, hierarchical organization of fiber cell wall components to yield precursors with dimensions in the nanoscale, high surface area, unique morphology, low density and mechanical strength. Overall, this contribution attempts to illustrate some exciting opportunities for cellulose and lignin from residual biomass.


21

LOCAL THERMAL CHARACTERIZATION OF NANOCELLULOSE FILMS COATED WITH INORGANIC THIN FILMS, DEPOSITED BY ATOMIC

LAYER DEPOSITION

MARIA SOLEDAD PERESINa, TIINA NYPELÖb, MATTI PUTKONENa, TEKLA TAMMELINa, ORLANDO ROJASb

aVTT Technical Research Centre of Finland, Espoo, Finland bDepartment of Forest Biomaterials in the College of Natural Resources at North Carolina State

(NCSU), Raleigh, North Carolina, USA [email protected]

ABSTRACT

Dense, smooth, self-standing nanofibrillated cellulose (NFC) films were coated at low temperatures with Al2O3 and TiO2 thin films. Differences on the surface of NFC films -during the initial stages of metal oxide growth- were studied using nano-thermal analysis (nano-TA) technique. Nano-TA is a valuable tool that allows the study of local thermal profiles based on local softening transition temperature determination, which can be related either to melting or glass transition temperature of the tested materials. In order to control and optimize the performance and structure of inorganic thin films on cellulosic substrates, a deep understanding of the interactions between the substrate and the ALD precursor is essential in order to investigate the potential of these materials in applications on the fields of cellulose-based sensors and flexible electronics. Additional properties of these hybrid materials can include enhanced moisture resistance; tuneable conductivity depending on the inorganic precursor utilized and enhanced thermo-mechanical properties.


22

CELLULOSE-INORGANIC HYBRID FILMS WITH THERMOELECTRIC PROPERTIES

BENJAMIN P. WILSONa, MATTI PUTKONENb, TANELI TIITTANENc, HUA JINc,

MARIE GESTRANIUSb, TIIA-MARIA TENHUNENb, MAARIT KARPPINENc, TEKLA TAMMELINb, EERO KONTTURIa,d,

a Department of Forest Products Technology, Aalto University School of Chemical Technology, P.O. Box 16300, FI-00076 AALTO, Finland

b VTT Technical Research Centre of Finland, P.O. Box 1000, FI-02044, Espoo, Finland c Department of Chemistry, Aalto University School of Chemical Technology, P.O. Box 16100,

FI-00076 AALTO, Finland

d Polymer and Composite Engineering (PaCE) Group, Department of Chemical Engineering, Imperial College London, London SW7 2AZ, United Kingdom

[email protected]

ABSTRACT As the world requires ever increasing levels of energy, the pressure to meet those demands in a more sustainable way also increases with time. Over the last decade, our ability to exploit numerous sources of renewable energy have undergone substantial technological and economic advances, however, plenty of work remains to keep this nascent infrastructure on a sustainable footing. Furthermore, this desired aim will not be achieved by any single technological solution but requires the combination of a diverse range of different energy efficient production methods.

The field of energy harvesting encompasses a number of methodologies that exploit ambient energy sources or waste heat energy and convert them to electric power for use in a variety of everyday applications like sensors, payment terminal and information signs. Examples of energy harvesting technologies include conversion of mechanical strain (piezoelectric devices) or light into electricity (photovoltaics). Another method that is seeing increasing interest is the field of thermoelectric materials, which have the ability to convert temperature gradients or waste heat into electricity (See Figure 1).

Figure 1: Schematic of a Thermoelectric Generator. In contrast to photovoltaics, which are already seeing widespread use, thermoelectric

generators have the most potential to further improve energy use and production. The


23

everyday application of these generators is held back due to low conversion efficiencies and a lack of suitable, non-toxic and cheap alternatives to the most widely used tellurium compounds. Nevertheless, recent research has demonstrated that nanostructured materials with sequential inorganic metal oxide and organic hydroquinone layers (produced by Atomic/Molecular Layer Deposition (ALD/MLD) methods) can display reasonable levels of thermoelectric behaviour [1,2].

In order to investigate if cellulose could also produce thermoelectric behaviour, a number of organic-inorganic hybrid materials - in which alternating nanometre thick layers of ZnO and cellulose derivatives - were produced systematically through a combined ALD-spin coating approach (Figure 2). The configuration of these materials were subsequently characterised by a number of methods including FT-IRRAS, AFM, XRR, whilst the electrical/thermodynamic behaviour was determined by investigation of their resistivity and Seebeck coefficients.

Initial results show that these cellulose-metal oxides display comparative levels of thermoelectric behaviour when compared to other organic-inorganic hybrids and thus could offer a sustainable and non-toxic alternative to current thermoelectric materials in the future.

Figure 2: Outline of a Cellulose-Inorganic thermoelectric nanolaminate.

REFERENCES [1] Tynell, T. and Karppinen M. (2013). ZnO:hydroquinone superlattice structures fabricated by ALD/MLD. Thin Solid Films, 551, 23-26. [2] Tynell, T. Yamauchi H. and Karppinen M. (2014). Hybrid inorganic-organic superlattice structures with atomic layer deposition/molecular layer deposition. Journal of Vacuum Science and Technology A, 32, 01A105.


24

POLYPHENOLS BASED MICROCAPSULES BY ULTRASONIC IRRADIATION

ELISAVET D. BARTZOKA, HEIKO LANGE, MARIO CARUSO, CLAUDIA CRESTINI,*

University of Rome 'Tor Vergata', Department of Sciences and Technologies, Via della Ricerca Scientifica, 00133 Roma, Italia

[email protected]

ABSTRACT Tannins and lignins are abundant biopolymers that possess unique hydrophobic interactions and complexing properties. Our studies aim at efficiently take advantage of such peculiar structural characteristics in the development of microcapsules for biomedical applications. Lignin and tannins microcapsules constitute promising matrices for targeted delivery due to the high biocompatibility of such biopolymers.

In our study, lignin and tannin capsules were obtained by ultrasonic irradiation using different surface areas, power and time of sonication (Cucheval and Chow 2008). To develop efficient capsules we focused on different types of lignins and tannins with different amounts of phenolic and aliphatic hydroxyl content, as determined by 31P NMR (Melone et al. 2013) (Sette, Wechselberger, and Crestini 2011). Ultrasound technology was used to emulsify the oil phase in the polyphenols aqueous solution and cause a crosslinking of the macromolecules (Tortora et al. 2014), also in the presence of Fe(III) salts as a templating reagent for polyphenols, so as to tune the crosslinking of the polyphenols and ,thus, the stability of the capsules.

In our presentation we will present comparative analysis results on the size and polydispersion index, crosslinking degree, stability, active uptake and in vitro release potential of encapsulated molecules in the different colloidal systems.

REFERENCES [1] Cucheval, A., and Chow, R.C. Y. (2008). A Study on the Emulsification of Oil by Power Ultrasound. Ultrasonics Sonochemistry 15 (5): 916–20.

[2] Melone, F., Saladino, R., Lange, H. and Crestini, C. (2013). Tannin Structural Elucidation and Quantitative 31P NMR Analysis. 1. Model Compounds. Journal of Agricultural and Food Chemistry 61 (39): 9307–15.

[3] Sette, M., Wechselberger, R. and Crestini, C. ( 2011). Elucidation of Lignin Structure by Quantitative 2D NMR. Chemistry – A European Journal 17 (34): 9529–35.

[4] Tortora, M., Cavalieri, F., Mosesso, P., Ciaffardini, F., Melone, F. and Crestini, C. (2014). Ultrasound Driven Assembly of Lignin into Microcapsules for Storage and Delivery of Hydrophobic Molecules. Biomacromolecules 15 (5): 1634–43.


25

WHEAT STRAW LIGNIN - SUCCESSIVE FRACTIONATION AND STRUCTURAL CHARACTERISATION

FLORIAN ZIKELIa, THOMAS TERSa, KARIN FACKLERa,

EWALD SREBOTNIKa, JIEBING LIb aVienna University of Technology, Institute of Chemical Engineering,

Getreidemarkt 9/166, a-1060 Vienna bRoyal Institute of Technology, KTH, se-100 44 Stockholm

[email protected]

ABSTRACT Ball-milling as a pretreatment method for a successive lignin isolation and fractionation was investigated using wheat straw. Different milling times and their effect on yields and structures of the isolated lignin fractions were analyzed in detail. As a consequence, a unique process for the fractionation of lignin from wheat straw is proposed: Ball-milling for 8 hours, followed by a direct and an acidolysis-assisted dioxane-water extraction. Four distinctly different lignin structures were thus obtained: 1) One free non-core lignin, termed Free Lignin (FL) which is a cellulose-lignin with lowest molar mass (Mw) and Klason Lignin (KL) content and highest contents of p-hydroxycinnamic acids (pHCAs), condensed phenolic hydroxyl groups and tricin moieties, and with a detectable amount of cinnamyl alcohol moieties; based on its structural characteristics this fraction was supposed to possibly play a role in the plant´s response to environmental stress like wounding or temporary and locally elevated solar irridation as a small, highly funcionalized, “free floating” and transportable lignin molecule. 2) two core xylan-lignins differing in their degree of xylan-branching as indicated by their xylose/arabinose ratios of > 4 (“linear xylan”) and ~ 2 (”branched xylan”), respectively, and showing higher KL contents as well as higher molar masses; based on their estimated monomeric ratios (by 2D HSQC NMR spectroscopy) and comparing with literature reports on topochemistry and ligninfication (Ralph et al. 1994; Donaldson 2001) differences in topochemical origin were supposed deriving either from the middle lamella or the secondary wall respectively. Further, these two xylan-lignins show differences in their pHCA association: linear xylan-lignin shows higher contents of FA while branched xylan-lignin is connected to pCA moieties. 3) one core cellulose-lignin which is the residual fraction resistant to all extractions and with the lowest KL content. Based on the mass balance of KL, the yields of these four fractions are 13.8%, 18.1%, 37.5% and 12.5%, respectively, thus accounting for 82% of the total KL in wheat straw. Without ball-milling, FL and branched xylan-lignin of wheat straw are accessible for direct and acidolysis-assisted dioxane-water extraction, respectively. The acidolysis facilitates the extraction via hydrolysis of carbohydrates (mainly hemicelluloses) and cleavage of some of the lignin benzyl ether structures to C-carbonyl structures (Gellerstedt et al. 1994). Ball-milling opens up the fibre structure so that the linear xylan-lignin becomes accessible for the direct dioxane-water extraction. Following the process proposed, wheat straw lignin can be fractionated and recovered nearly


26

quantitatively with well-preserved structures as indicated by very high β-O-4´-linkages, low free phenolic contents, and stable molar masses inside the range of the investigated ball-milling times.

REFERENCES

[1] Donaldson, L. A. (2001). Lignification and lignin topochemistry -- an ultrastructural view. Phytochemistry 57(6): 859-873. [2] Gellerstedt, G., J. Pranda and E. L. Lindfors (1994). Structural and molecular properties of residual birch kraft lignins. Journal of Wood Chemistry and Technology 14(4): 467-482. [3] Ralph, J., R. D. Hatfield, S. Quideau, R. F. Helm, J. H. Grabber and H.-J. G. Jung (1994). Pathway of p-Coumaric Acid Incorporation into Maize Lignin As Revealed by NMR. Journal of the American Chemical Society 116(21): 9448-9456.


27

AFFIBODY FUNCTIONALIZED BACTERIAL CELLULOSE TUBES FOR BIOFILTRATION APPLICATIONS

HANNES ORELMA*a, LUIS O. MORALESa, LEENA-SISKO JOHANSSONa,

INGRID C. HOEGERb, ILARI FILPPONENa, CRISTINA CASTROc, ORLANDO J. ROJASa,b, JANNE LAINEa

aAalto University, School of Science and Technology, Faculty of Chemistry and Material Sciences, Department of Forest Products Technology, FI-00076, Espoo, Finland.

bNorth Carolina State University, Departments of Forest Biomaterials and Chemical and Biomolecular Engineering, Raleigh, NC 27695, USA.

cSchool of Engineering, Universidad Pontificia Bolivariana, Circular 1 # 70-01, Medellín, Colombia. [email protected]

ABSTRACT

The objective of this study was to develop a tubular nanocellulosic biofilter by using affibodies to selectively catch proteins (Figure 1). Affibodies are engineered proteins (Löfblom et al. 2010), grown with E.coli, which mimic the antigen binding properties of native antibodies. They have also a wide availability to industrial applications due to their bacterial origin. Tubular nanocellulosic matrices (Bodin et al. 2007) were achieved by growing them with Gluconacetobacter Medellinensis in the presence of carboxymethyl cellulose (CMC) to in-situ modify grown BC fibrils (Haigler 1982). The properties of BC tubes were characterized with SEM, WRV, charge, and XPS measurements. The concept was demonstrated with anti-human serum albumin (anti-HSA) affibodies, which bind specifically HSA. Affibodies were covalently conjugated onto CMC modified BC tubes with the aqueous EDC/NHS conjugation chemistry. The conjugation of affibody and its affinity reactions on CMC modified cellulose were verified by Surface Plasmon Resonance (SPR) with cellulose thin films. The specific binding of HSA on an affibody functionalized BC tube was demonstrated with fluorescence stained HSA and the fluorescence microscopy. The presence of CMC in the culture medium within BC grow has a significant effect on the WRV of never-dried and air-dried BC tubes. This subsequently reduces the irreversible structural changes of grown BC within drying. Altogether, the covalent conjugation of affibodies onto the surface of BC tubes and subsequent detection of HSA was demonstrated (Orelma et al. 2014). The fluorescence intensity of bound HSA on affibody functionalized BC tubes increased linearly as a function of HSA concentration. It is expected that the developed mild and generic methodology can be effortlessly transformed and utilized for the specific detection and separation of other target proteins.


28

Figure 1: Schematic illustration of the preparation of CMC-modified bacterial cellulose tubes (BC tubes) and their subsequent functionalization with affibodies for biofiltration applications.

REFERENCES [1] Bodin A., Bäckdahl H., Fink H., Gustafsson L., Risberg B., Gatenholm, P. (2007). Influence of Cultivation Conditions on Mechanical and Morphological Properties of Bacterial Cellulose Tubes. Biotechnology and Bioengineering, 97(2), 425-434. [2] Haigler C. H., White A. R., Brown R. M., Cooper K. M. (1982). Alteration of in vivo cellulose ribbon assembly by carboxymethylcellulose and other cellulose derivatives. Journal of Cell Biology. 94(1), 64-69. [3] Löfblom Jl, Feldwisch J, Tolmachev V, Carlsson J, Ståhl S, Frejd FY. (2010). Affibody molecules: engineered proteins for therapeutic, diagnostic and biotechnological applications. FEBS Lett. 584(12), 2670-2680. [4] Orelma H., Morales L.O., Johansson L-S., Hoeger I. C., Filpponen I., Castro C., Rojas O., Laine J. (2014) RSC Advances. 4, 51440-51450.


29

ECTOPIC LIGNIFICATION IN THE FLAX LIGNIFIED BAST FIBER MUTANT

CHABBERT Ba, CHANTREAU Mb, KIYOTO Sc, YOSHINAGA Ac, BOERJAN Wd, MESNARD Fe, HAWKINS Sb

aINRA, UMR614 Fractionnementd es AgroRessources et Environnement, F-51100 Reims, France bUniversité de Lille 1, UMR 8576 CNRS Glycobiologie Structurale et Fonctionnelle,

F-59650 Villeneuve d'Ascq, France cDivision of Forest and Biomaterials Science, Kyoto Univ., Kyoto, Japan

dDepartment of Plant Systems Biology, VIB, Technologiepark 927, 9052 Gent, Belgium eUniversité de Picardie Jules Verne, EA 3900, BIOPI Phytotechnologie, F-80037 Amiens, France

[email protected]

ABSTRACT

Flax is a fiber crop producing highly contrasted secondary cell wall structures in the stem. Cells from the inner xylem core have heavily lignified secondary cell walls containing almost 30 % lignin whereas the thick secondary cell walls of the long bast fibers present in outer stem tissues are hypolignified and contain less than 4 % lignin (Day et al., 2005). Despite the existence of these highly contrasted secondary cell wall structures, hardly anything is known about the underlying molecular mechanisms regulating lignin biosynthesis and deposition in flax. In order to increase our knowledge about this process we have created a flax EMS mutant population (Chantreau et al., 2013). Histochemical screening led to the identification of 93 independent M2 mutant families showing pronounced ectopic lignification in the secondary cell wall of stem bast fibers (Figure 1). Wenamed this core collection the Linum usitatissimum (flax) lbf mutants for lignified bast fibers. We characterized the lbf1 mutant and showed that the lignin content increased from 3-5% up to 17% DM in outer stem tissues containing bast fibers but was unchanged in inner stem tissues containing xylem. Whole-genome transcriptomics suggested that ectopic lignification of flax bast fibers could be caused by increased transcript accumulation of some monolignol biosynthesis genes, lignin-associated peroxidase genes, and genes involved in H2O2 supply. 2D NMR and immunolabelling with KM1 (Figure 2) indicated that bast fiber ectopic lignin was highly condensed and rich in G-units. The lbf1 mutants also showed changes to other cell wall polymers as indicated by polysaccharide analysis (Figure 3), immunocytochemistry and confocal microscopy approaches. Preliminary study of the physicochemical properties showed that ectopic lignified fibers isolated from the lbf1 mutant could sorb as much water as the non-lignified fibers from WT, indicating that fiber properties rely on complex architecture of the cell walls relying on not only polymer content but also polymer interactions (Muraille et al., 2015).

Figure 1: Phloroglucinol staining of lignin in stem tissues of wild-type and lbf1 mutants

WT lbf

xylem

fibers


30

Figure 2: Immunogold silver staining of bast fibers from WT (A) and lbf1 mutant (B) with lignin antibody KM1. CCML, cell corner middle lamella; SW, secondary wall; L, lumen. Smaller photos (i

and ii) show a zoom of the regions indicated on main photo. Bars = 1 mm (main) and 0.15 mm (small)

Figure 3: Relative content of different sugars in outer tissues of wild-type and lbf1 mutants

REFERENCES

[1] Chantreau, M., Grec, S., Gutierrez, L., et al (2013) PT-Flax (phenotyping and TILLinG of flax): development of a flax (Linum usitatissimum L.) mutant population and TILLinG platform for forward and reverse genetics. BMC Plant Biology, 13(1), 159. [2] Chantreau, M., Portelette, A., Dauwee, R. et al (2014) Ectopic lignification in the flax lignified bast fiber1 mutant stem is associated with tissue-specific modifications in gene expression and cell wall composition. The Plant Cell, 26: 4462–4482. [3] Day, A., Ruel, K., Neutelings,G., Crônier, D., David H., Hawkins,S., Chabbert, B. (2005) Lignification in the flax stem: evidence for an unusual lignin in bast fibers Planta. 222: 234-245. [4] Muraille, L., Pernes, M, Habrant, A., Serimaa, R., Molinari, M., Aguié-Béghin, V., Chabbert, B. (2015) Impact of lignin on water sorption properties of bioinspired self-assemblies of lignocellulosic polymers. European Polymer Journal, 64: 21–35. This work was carried in the context of and financed by the French national project PT-Flax (ANR-09-GENM-020)and get financial support of the Kyoto University Foundation. Authors acknowledge the technical support of the PICT IBiSA biological imaging center (transmission electron microscopy) and the PLANET analytical platform (NMR) at the University of Reims Champagne-Ardenne.

Poster presentations

COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015 Poster presentations

31

POLYMERIC SORBENTS MANUFACTURED BY SYNTHYSIS OF LIGNIN

ACRYLATES WITH STYRENE AND DIVINYLBENZENE

B. PODKOŚCIELNAa, O. SEVASTYANOVAb B. GAWDZIKa, M. SOBIESIAKa

aMaria Curie-Skłodowska University,Department of Polymer Chemistry, Lublin, Poland bKTH, Royal Institute of Technology, Department of Fibre and Polymer Technology,

Stockholm, Sweden [email protected]

There is a growing interest to find a high-value application for the industrial lignins. The structural features of lignin have a high potential for chemical modifications, which can lead to value added polymeric materials with specific properties (Dournel et al. 1988; Hatakeyama and Hatakeyama 2010). The purity, homogeneous molecular weight and optimal number of reactive functional OH-groups in the lignin raw material are important parameters having the impact on the efficiency of the modification reaction.

Type and quantity of functional OH-group in kraft lignin used in present study (Fig.1) were determined by quantitative 31P NMR and shown in Table 1 (Podkościelna et al. 2015).

OCH3

H

SH

OHphen

OHaliph

(or lignin)

lignin

Lignin (L-OH) =

L-O

O

LA

L-O

OH

O

O

LEA

Figure 1: Shematic structure of kraft lignin molecule

Figure 2: Chemical structure of lignin derivatives: LA-modified with acrylic acid, LEA-modified with

epichlorohydrin and next with acrylic acid.

Esterification is one of the common approaches for the OH group modification (Laurichesse and Avérous 2014). The reaction with acrylic or methacrylic acid is one of the possible types of modifications resulting in the introduction of vinyl groups, capable for polymerization, into lignin structure. Subsequent lignin derivatives, LA and LEA, (Fig. 2) were copolymerized with styrene (St) and divinylbenzene (DVB) in the aqueous medium in suspension-emulsion procedure (Podkościelna et al. 2012, (Podkościelna et al. 2015) to produce porous microspheres. Lignin-modified microspheres are expected to possess following functional groups coming from lignin molecule on the surface: -OH, -OCH3, -SH (see Fig.3).


32

Table 1. Amount of functional groups in lignin (based on 31P NMR) and chemical composition of unmodified lignin (L) and lignin modified with acrylic acid (LA) and epichlorohydrin and acrylic acid (LEA) (based on and elemental analysis).

Functional group (mmol g-1) Composition (%) L LA LEA OHaliph 2.43 C 62.64 59.07 59.81 OHphen condensed 1.54 H 5.92 6.44 6.49 OHphen guiacyl 1.91 N 0.58 0.36 0.22 OHphen total 3.45 S 2.53 1.17 0.63 COOH 0.44 Total 71.67 67.04 67.16

The presence of sulphur in original lignin and lignin derivatives, LA and LEA, was confirmed by elemental analysis (Table 1).

Figure 3: Schematic representation of the copolymerization of lignin and its acryl derivatives (LA and LEA) with St and DVB.

The actual shapes of the obtained lignin-containing microspheres were observed by SEM, which showed that particles with diameters in the range of 10-30 μm were formed. Due to the presence of specific functional groups and the well-developed pore structure, the obtained Lignin-St-DVB microspheres may have potential application as specific sorbents for the removal of phenolic pollutants from water, as demonstrated by the solid-phase extraction (SPE) technique.

REFERENCES

[1] Dournel, P., Randrianalimanana, E., Deffieux, A., Fontanille, M. (1988): Synthesis and polymerization of lignin macromonomers I. Eur. Polym. J., 24:843-847. [2] Hatakeyama, H., and Hatakeyama, T. (2010): Lignin structure, properties and applications, Adv. Polym. Sci. 232:1-63. [3] Laurichesse, S., Avérous, L. (2014): Chemical modifications of lignins: Towards biobased polymers, Prog. Polym. Sci. 39:1266-1290). [4] Podkościelna, B., Bartnicki, A., Gawdzik, B. (2012) New crosslinked hydrogels derivatives of 2-hydroxyethyl methacrylate: Synthesis, modifications and properties. Express Polym. Lett., 6(9):759-771. [5] Podkościelna, B., Sobiesiak, M., Zhao, Y., Gawdzik, B., Sevastyanova, O. (2015): Preparation of lignin-containing porous microspheres through the copolymerization of lignin acrylate derivatives with styrene and divinylbenzene, Holzforschung (accepted January 2015).

CH2 CH2

CH2

+ +

Lor SH

St DVBOH

LEA

LA or

CH3O


33

TOWARDS IMPROVEMENT OF SELF-ASSEMBLED FUNCTIONALIZED LIGNOCELLULOSIC COMPOSITE BY CELLULOSE MICROFIBER LAYER

EWELINA CZUBAK, GRZEGORZ KOWALUK

Warsaw University of Life Sciences, Faculty of Wood Technology, Nowoursynowska str. 159, 02-787 Warsaw, Poland

[email protected], [email protected]

ABSTRACT

In hardboard technology, to achieve high mechanical properties of product, there is necessity to use fibers of a low grind ratio. Since hardboards are basically produced without a bonding agents, which could influence the mechanical features of panel, the fibers self-assembling connection strength depends mostly on fibers’ size. Large fibers, although stiffer and stronger, do not allow for smooth and properly homogeneous surface perform. This disadvantageous feature effects in difficult finishing, which require e.g. a larger amount of fillers and base lacquer use. When small fibers are used for production of hardboard panel with smoother surface, the bending strength and modulus of elasticity significantly decreases.

The idea for improving of hardboard surface properties, without strength losing, presented in this work, was to apply of thin face layer containing cellulose microfibers on the regular core hardboard mattress. The origin of Miscanthus x giganteus by-product cellulose fibers (Fig. 1), applied for face layer, was technology of biomass conversion performed by Haverty et al. 2012. The added value of application of waste cellulose fibers, apart from above mentioned goals, is utilization of by-product to production of panels of improved properties, and that the obtained composite surface is brighter, what could be desirable since the composite must be finished by thin layer of light materials (lacquers, foils etc.).

In the range of research a number of composites were produced with different thickness of microcellulose fiber layer. The mechanical properties of the panels were measured (modulus of rupture, modulus of elasticity), as well as physical features, as follow: water absorption, thickness swelling, density profile, surface absorption and surface roughness.


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Figure 1: Cellulose microfibers for composite face layers modification

REFERENCES [1] Haverty, D., Dussan, K., Piterina, A.V., Leahy, J.J. and Hayes, M.H.B. (2012). Autothermal, single-stage, performic acid pretreatment of Miscanthus x giganteus for the rapid fractionation of its biomass components into a lignin/hemicellulose-rich liquor and a cellulase-digestible pulp. Bioresource Technology 109, 173–177.


35

ISOLATION AND CHARACTERIZATION OF ACETYLATED XYLAN FROM SUGARCANE BAGASSE

DANILA MORAIS DE CARVALHOa,b, ANTONIO MARTINEZ ABADc, FRANCISCO JAVIER VILAPLANA DOMINGOc,d, MIKAEL E. LINDSTÖMb, JORGE LUIZ COLODETTEa, OLENA

SEVASTYANOVAb,d

aPulp and Paper Laboratory, Department of Forestry Engineering, Federal University of Viçosa, Brazil

bDepartment of Fibre and Polymer Technology, KTH, Royal Institute of Technology, Stockholm, Sweden

cBiotechnology/Glycoscience Division, KTH, Royal Institute of Technology, Stockholm, Sweden dWallenberg WOOD Science Center, KTH, Royal Institute of Technology, Stockholm, Sweden

[email protected]

ABSTRACT Sugarcane bagasse is an important lignocellulosic waste generated by sugarcane industry. The forecast in Brazil for 2014/15 is to produce 659 million tons of sugarcane; as a result, an approximately 92 million tons of bagasse (stalks after the juice extraction) are expected to be generated in the same period (Conab, 2014). Bagasse represents a considerable source of xylan corresponding with 27 % of dry material (Rocha et al., 2011,). The information on the chemical structure of bagasse xylan is important to contribute to the basic knowledge about hemicelluloses in non-wood biomass as well as for a better understanding of their behaviour in the chemical processing of non-wood raw materials. This knowledge may also open new possibilities for biomaterial applications. This study aims to evaluate the chemical and structural properties of acetylated xylan isolated from sugarcane bagasse. The isolation of xylan in intact form and representative amounts is a crucial factor for the chemical characterization. Delignification by peracetic acid (PAA) or sodium chlorite (NaClO2) were used in this work to produce a hollocellulose from extractive-free sawdust. Subsequently, xylan was extracted with dimethyl sulfoxide (DMSO). The yield of xylan obtained by the DMSO extraction of PAA-hollocellulose was almost 7 times higher than that obtained after similar extraction of the NaClO2-hollocellulose. The acetylated xylan was thoroughly characterized by carbohydrate analysis after the acid hydrolysis, 1H nuclear magnetic resonance (NMR) spectroscopy, and Fourier transform infrared (FTIR) spectrometry. The xylan was the main component extracted by DMSO in this work, however the composition was different for xylan samples isolated from NaClO2-holocellulose and PAA-holocelluloses. Xylan sample extracted from PAA-holocellulose contained a higher amount of xylose as it was shown by carbohydrate analysis.


36

The FTIR spectra of holocellulose and extracted xylan samples are shown in Fig. 1A. Strong absorption bands due to C-O-H vibrations can be observed for all samples at 3700-3000 cm-1 and 1200-1000 cm-1 region. The strong sharp band at 1730 cm-1, which is more pronounced for the isolated xylans, corresponds to acetyl C=O ester bond and the weak band at 897 cm-1 to C-H deformation in β-linked glucosidic bond. The NMR spectrum showed the typical signals of glycosidic ring (5.5-3.0 ppm) and acetyl group (next to 2.0 ppm) (Fig. 1B).

Figure 1: A) FTIR spectra of a) bagasse PAA-holocellulose, b) NaClO2-holocellulose; c) hemicellulose isolated by DMSO from PAA-holocellulose; d) hemicellulose extracted by DMSO from

NaClO2- holocellulose. B) 1H NMR spectrum of bagasse hemicellulose extracted by DMSO from PAA-holocellulose (solvent is DMSO-d6)

REFERENCES [1] Conab. Companhia nacional de abastecimento, 2014 [cited 2014 http://www.conab.gov.br/OlalaCMS/uploads/arquivos/14_08_28_08_52_35_boletim_cana_portugues_-_2o_lev_-_2014-15.pdf].

[2] Rocha, G.J.M., Martin, C., Soares, I.B., Souto Maior, A.M., Baudel, H.M., Abreu C.A.M.de (2011). Dilute mixed-acid pretreatment of sugarcane bagasse for ethanol production. Biomass and Bioenergy, 35 (1), 663-670.

A B


37

UNDERSTANDING INTERNAL FIBER DEVELOPMENT DURING TMP REFINING OF SULPHITE PRETREATED SPRUCE CHIPS

DINESH FERNANDOa, ERIK NELSSONb, GEOFFREY DANIELc

aDepartment of Forest Products, Swedish University of Agricultural Sciences (SLU), P.O. BOX 7008, SE-750 07 Uppsala, Sweden

bHolmen Paper AB, Bravikens Pappersbruk, 601 88 Norrköping, Sweden [email protected]

ABSTRACT

Production of paper products like newsprint of suitable quality using mechanical pulping (MP) is a highly demanding process in which high paper strength and optical properties needs to be produced with lowest possible energy expenditure. To this end the thermomechanical pulp (TMP) process is largely practiced in MP mills due to its unique refining process that produces pulps with a desirable combination of strength (tensile index) and light scattering properties. However, the increasingly high electrical energy cost of the process is a critical issue which has accelerated the development of new process solutions including new segment designs, Advanced Thermomechanical pulping (ATMP) and chemical pre-treatments. One approach is low dosage sulphite chip pre-treatment which has been shown to reduce ca 30% specific energy consumption (SEC) during double-disc (DD) TMP refining compared to targeted tensile strength (Nelsson et al. 2011). In comparison to the majority of work on process-property relationships, it is also of prime importance to understand fundamentals related to the behaviour/response of wood fibres at the cell wall level (e.g. internal fibre development (IFD)). This fundamental knowledge provides insights connecting processes to products and thereby potential for tailoring, optimization and energy efficiency. Characterization of IFD in TMP pulps from a mill scale trial using Norway spruce aimed at reducing energy consumption by combining low dosage sulphite chip pre-treatment and high intensity refining in a modern TMP-line at Holmen Paper, Braviken, Sweden, was carried out in the present work. Different pulps refined to low freeness (60-190 ml) were produced from wood chips impregnated with different dosages (0, 0.12, 0.24, 0.61 and 1.2%) of Na2SO3 at pH 9 before pre-heating and one-stage refining at different SEC levels (ca 1750-2100 kWh/bdt) using a DD-TMP refiner. Six samples were chosen for pulp and paper property analyses which showed the addition of low-dose sulphite increased tensile index, elongation, density and brightness while lowering shive content and light scattering when compared at certain SEC. Sulphite addition improved energy efficiency of TMP refining by lowering ca 15% refining energy at a tensile index of ca 47 Nm/g compared with pulp produced without sulphite treatment.


38

In-depth analysis on IFD of the pulps was performed by assessing and statistically analysing the degree of delamination/internal fibrillation (D/IF; represents the major structural changes within the secondary wall of native stiff fibres) according to Fernando and Daniel’s (2010) method of Simons’ staining (SS). Based on degree of D/IF development in the fibre cell wall during processing, MP fibres stain different colour intensities ranging from light blue, dark blue, green and orange/yellow with latter characterizing the most developed fibres. The method transforms the qualitative information on colour changes into quantitative data and thereby quantifies IFD and allows statistical analysis of MPs with respect to degree of D/IF development. Results showed that sulphite pretreatment effectively increases D/IF of the respective pulp. For example, the pulp refined after highest sulphite dosage in combination with highest energy input was dominated by treated fibres (ca 65%), the majority of which were “high D/IF” fibres (ca 39%) representing the most flexible fibres in a MP. Interestingly, the SS method revealed that fibre populations of the two pulps refined with highest SEC without sulphite treatment and with highest dosage of sulphite but much lower SEC were more or less similar in respect of IFD (52% and 55% treated fibres with D/IF developed, respectively). Furthermore, statistical analysis indicated that both sulphite treatment and increasing SEC have a significant impact on inducing wall D/IF, making pulp fibres flexible and thereby improving conformability and collapsibility of the pulp. In addition, it was confirmed statistically that there was a similar IFD in the two pulps produced from the highest SEC without sulphite addition and low energy input after low sulphite dosage of 1.2%; the two pulps exhibiting almost the same tensile strength. The results from SS revealing changes in D/IF development explained most of the property development of the pulps including tensile strength, elongation and density and gave statistical evidence for the improved energy efficiency associated with sulphite pretreatment.

REFERENCES [1] Nelsson, E., Hildén, L., Sandberg, C., Fernando, D. and Daniel, G. (2011). Mill scale experiences of combined sulphite pre-treatment and high intensity refining of spruce. Proceedings IMPC 2011, Xi’an, China, pp. 182-186. [2] Fernando, D. and Daniel, G. (2010). Characterization of spruce thermomechanical pulp (TMP) at the fibre cell wall level: a method for quantitatively assessing pulp fibre development using Simons’ stain. TAPPI J. 8:47-55.


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REVEALING OF LIGNIN STRUCTURE-ANTIOXIDANT ACTIVITY RELATIONSHIP USING ANALYTICAL PYROLYSIS AND CHEMOMETRY

JEVGENIJA PONOMARENKO, TATIANA DIZBITE, MARIS LAUBERTS,

GALINA DOBELE, GALINA TELYSHEVA Latvian State Institute of Wood Chemistry, 27, Dzerbenes Street, Riga, Latvia, lv-1006

[email protected]

ABSTRACT The present work describes the searching of structure - antioxidant activity relationship (SAR) for technical lignins for future development of a theoretic basis for their effective application as antioxidants for living organisms and variety of materials. Demand for natural antioxidants is constantly increasing, therefore, the search for new renewable resources for the manufacture of antioxidants is an urgent task. Polyphenols are the most widely spread natural antioxidants. With increasing information about the antioxidant activity of plant phenols, the formation of the data bases and the establishment of quantitative structure-activity relationships (QSAR) become necessary. At present, flavanoids, lignans, stilbenes and phenolic acids are well characterized as antioxidants, whereas systematic investigations of lignins in this aspect are performed much more seldom. The establishment of the SAR of lignin and other natural polymeric phenols is accomplished by the difficulty of the characterization of their structure, as well as the impossibility to express the antioxidant activity per mole of compound. The aim of the present work was to characterize and quantify the structure–antioxidant activity relationship (SAR and QSAR, respectively) for lignins. With this aim, the antioxidant activities of 50 different technical lignins have been determined using tests with DPPH and ABTS+ free radicals, which react with phenols by different mechanisms. It has been proven that, expressing the antioxidant activity of lignins in the test with stable free radicals as the mole of deactivated radicals per one mole of lignin OH phenolic group, it is possible to describe SAR best of all. The lignins of various botanical origins (annual plants, coniferous trees, deciduous trees) were isolated and fractionated by different techniques (delignification by alkali, kraft process, fast pyrolysis, hydrolysis). The structure and functionality of lignins were characterized by functional group analyses (phenolic OH, carboxyl and methoxyl groups), analytical pyrolysis (Py-GC/MS/FID), electron paramagnetic resonance (EPR) and size exclusion chromatography (SEC). Those structural properties, which may influence the antioxidant activity, namely: the content of G+S phenols, the content of the phenylpropane units (PPU) with the –CH2 groups in the a-positions of the side chains, the content of the PPU with the O-containing groups in the side chains, the content of the carbohydrates, the (ArC1+ArC2)/ArC3 proportion, the size of the π-conjugated systems, Mw, the content of the metoxyl groups, the content of PPU with the double bonds in the a-positions of the side chains were investigated in detail.


40

In studies of the structure-activity relationships, it is necessary to take into account the heterogeneity of the samples. The PCA (“Principal Component Analysis”) method was used to classify the lignin samples according to their structural properties. The chosen structural properties, together with the number of the samples, allowed to join all lignins in one group, without dividing them into clusters, depending on the botanical origin and/or the processing method. The classification of the samples under study is shown in Fig. 1. Each lignin sample is marked by the number 1-50. Loadings of the data to other principal components’ coorinates also did not allow separating them in several groups.

Figure 1. Loadings of the lignins in PC1 and PC2 The relationship between the lignin structure and antioxidant activity was characterized by pair correlation, partial correlation, and multivariate regression analyses, including correlated components regression (CCR). The results were compared with those of lignin model compounds and low molecular weight phenylpropanoids. The structure related antioxidant activity of lignins has been quantified. The results of the studies have shown that the combination of the ABTS●+ and DPPH● tests allows describing the SAR of lignins, taking into account both proton coupled electron transfer (PCET) and sequential electron transfer mechanisms (SPLET). For the first time, models for the quantitative characterization of the lignins’ structure-antioxidant activity (QSAR) were obtained. The SAR and QSAR obtained can be used for the evaluation of the thermodynamic reactivity of lignins in the reaction with oxidants. They are also useful for adequate prediction of the antioxidant activity of lignins based on their structural analysis and for the tuning of lignin antioxidant properties.

ACKNOWELEGEMENTS

This work has been supported by the European Social Fund within the project «Support for Doctoral Studies at University of Latvia» and the Latvian budget, Latvian Scientific Council grant 564/2012 and Government Research Program (ResProd) 2014-2017.

L-1L-2L-3L-4

L-5L-6

L-7

L-8L-9

L-10

L-11

L-12

L-13L-14

L-15

L-16

L-17

L-18L-19

L-20L-21L-22

L-23L-24

L-25

L-26L-27

L-28

L-29L-30

L-31

L-32

L-33L-34L-35L-36L-37L-38

L-39L-40

L-41L-42

L-43L-44

L-45L-46L-47L-48L-49L-50

-6

-4

-2

0

2

4

6

-8 -6 -4 -2 0 2 4 6 8 10

PC

2

PC 1


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CATIONIC AND ANIONIC NANOFIBRILLATED CELLULOSES FOR PAPERMAKING

GÜLIZ HOCAOĞLU* AND SEDAT ONDARAL

Karadeniz Technical University, Faculty of Forestry, Forest Product Engineering, Dept. Pulp Paper

Technology 61080 Trabzon, Turkey [email protected]

ABSTRACT

The nanofibrillated cellulose, which is one of the most abundant and sustainable material, is produced by delamination of wood fibres via intense mechanical shearing forces promoted by pre-treatment with chemicals and/or enzymes and has been attracted growing attention for different purposes (Kalia et al., 2014). The cationic and anionic nanofibrilated celluloses were prepared by using a bleached sulphite pulp and their adsorption properties and effects on paper strength were investigated in this study. Cationic nanofibrilated cellulose (CNFC) and anionic nanofibrilated cellulose (ANFC) produced from bleached sulphite softwood fibres pre-treated with 3-chloro-2-hydroxypropyltrimethylammonium chloride and 2,2,6,6-Tetramethylpiperidin-1-oxyl (TEMPO) oxidation, respectively. The adsorption properties of CNFC and ANFC on silicon oxide surface were studied by means of Quartz Crystal Microbalance with Dissipation (QCM-D) in terms of adsorbed mass and viscoelastic properties. These fibrillated celluloses were also used as dry strength additive. ANFC was applied together with CNFC or poly(amidoamine epichlorohydrin) (PAE) and both dry and wet strength properties of paper promisingly increased.

Figure 1. AFM images of ANFC and CNFC (1µm x1µm).

REFERENCES [1] Kalia, S., Boufi, S., Celli, A., Kango, S. (2014). Nanofibrillated cellulose: surface modification and potential applications, Colloid and Polymer Science, 292(1), 5-31.


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SOLVENTS FOR CELLULOSE: INSIGHT FROM COMPUTER SIMULATION

ADAM HARDYa, THOMAS ROSENAUb, HENRY BOCKa aHeriot Watt University, UK

bUniversity of Natural Resources and Life Sciences, Austria [email protected]

ABSTRACT

The development of greener solvents for cellulose requires thorough molecular-level understanding of the dissolution process. We combine experiments and computer simulation to provide this insight. Hydrogen bonds are significant contributor to the interactions between cellulose chains. Thus, to separate the chains from each other, these hydrogen bonds need to be disrupted. This requires attack of the donor or acceptor atoms with compatible functional groups of the solvent. A number of solvents have been found to achieve this, but they are generally environmentally harmful. The first step towards the design of better solvents is to gain understanding of how solvents disrupt cellulose/cellulose hydrogen bonds and then integrate this functionality in less harmful molecules. The presented project uniquely combines solvent tests, high-resolution solid-state NMR and computer simulations. This allows us to link microscopic structural information to macroscopic function and to take advantage of the complementing microscopic insight from experiment and simulation.


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DETERMINATION OF MOLECULAR WEIGHTS OF LIGNINS: ACCURACY AND PRECISION ASPECTS

HEIKO LANGE, CLAUDIA CRESTINI*

Department of Chemical Sciences and Technologies; University of Rome ‘Tor Vergata’; Via della Ricerca Scientifica; 00133 Rome; Italy


ABSTRACT GPC-based determination of molecular mass key data describing lignin samples, namely the number average molecular weight Mn, the weight average molecular weight Mw, and the polydispersity PD, is difficult, and has been subject to discussions and optimisations for decades, without yet yielding a convincing concept. Nonetheless, knowledge of the mentioned key data, especially the PD for a given lignin sample, is mandatory for matching material and applications. We have developed a transparent and robust protocol for the gel-permeation chromatography-based characterisation of plant-derived polyphenols in general, and lignins in particular. In comparative studies, we systematically evaluated

i) the influence of the range of molecular weights used for the calibration of the analytical set-up,

ii) the influence of the flow-rate on the molecular mass-related key figures of certain lignin samples,

iii) the influence of the nature of the detector used for recording, iv) the influence of the functionalisation, also with respect to structural

changes accompanying these functionalisations v) the influence of additives.

We propose a generally applicable method and set-up for determining molecular weight key-figures based on GPC. For standard lignins, that are well studied and generally regarded as benchmark standards, we obtain data comparable to NMR-based estimations (Crestini et al. 2011, Sette et al. 2011).

REFERENCES [1] Crestini, C., Melone, F., Sette, M., Saladino, R. (2011). Milled wood lignin: A linear oligomer. Biomacromolecules 12(11), 3928-3935. [2] Sette, M., Wechselberger, R., Crestini, C. (2011). Elucidation of lignin structure by quantitative 2D NMR. Chemistry – A European Journal 17(34), 9529-9535.


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STRUCTURAL EVALUATION OF MATERIALS BASED ON XANTHAN GUM AND LIGNIN

IRINA ELENA RASCHIP, MARIA-CRISTINA POPESCU

Petru Poni Institute of Macromolecular Chemistry, Iasi, Romania [email protected]

ABSTRACT

This work was intended to develop crosslinked xanthan gum/lignin hydrogel systems, to characterize the new materials, and to explore their potential applications. Crosslinked xanthan gum/lignin hydrogels were synthesized with various lignin types (softwood sulfur free HpH, softwood curan 100, softwood pine, lignin from annual plants, aspen wood lignin.) Scanning electron microscopy was used to determine the morphology of the xanthan/lignin hydrogels and evidenced a high porosity formation. The lignin type influences the morphology which is either fibrilar as in case of hydrogel containing aspen wood lignin (which has the highest content of COOH groups and lowest content of phenolic OH groups) or smooth surface for the others. Structural evaluation has been done by FT-IR spectroscopy. Interactions between the two components leading to the formation of new hydrogen bonds and of crosslinked structure of the hydrogels, were observed. The energy of the hydrogen bonds is higher for the hydrogel containing aspen wood lignin suggesting stronger intermolecular interactions. Apart of the morphological and structural features, the swelling properties of the hydrogels were evaluated by dynamic water vapour sorption and by direct immersion of the samples in water.


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MODIFICATIONS OF CELL WALL PROPERTIES BY PRODUCTION OF RECOMBINANT RESILIN COMPOSITES IN TRANSGENIC PLANTS

ITAN PREIS, SHAUL LAPIDOT, MIRON ABRAMSON AND ODED SHOSEYOV

Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Israel, Rehovot, Israel.

[email protected]

ABSTRACT The quality and characteristic of wood based products are determined by the fibers properties, as the fiber cell wall define the industrially important quality parameters such as tensile strength, elongation, elasticity, stiffness and resilience. A potential approach for improving fiber and derived products properties is modification of the fiber cell wall. Here we describe the expression of recombinant resilin, an elastic protein, in the cell wall of transgenic plants. Resilin is a polymeric rubber-like protein, secreted by insects to specialized cuticle regions. Its unique mechanical properties allow, among others, the outstanding jumping ability of fleas, up to 30 cm high. The elastic properties of resilin are achieved by formation of di-tyrosine bridges within resilin monomers and cuticle polysaccharides, generated by peroxidase enzymes, in the insect cuticles. This highly resilience and elastic protein was optimized for expression in tobacco and was directed to the cell wall by a signal peptide. Cross-linking of resilin to the cell wall polyphenols was enabled by utilizing the presence of natural plant cell wall peroxidases. Resilin was located in the cell wall by immunohistochemistry. Increase in typical di-tyrosine blue florescence of the cell wall, indicates resilin polymerization and cross-linking. The integration of resilin to the cell wall changed the mechanical properties of the plant tissue. Transgenic stems showed reduction in young`s modulus and an increase in the ability to strain before failure. Moreover, changes in the formation of the plant cell wall, possibly due to the cross-linking of resilin, improved sugars release from plant material. Tobacco is a model plant in this research. Transformation of resilin to eucalyptus trees is currently in progress. Such transgenic trees can be wind resilient and used in the future for production of elastic wood and fibers from transgenic forest, for the paper and wood products industry and for replacement of synthetic materials, with biodegradable ones In addition, resilin was shown to cross link with coniferyl alcohol in vitro, in the presence of Horseradish Peroxidase (HRP) and under oxidative conditions, similar to the natural synthesis process of lignin in the cell wall. Next we plan to mimic the transgenic cell wall structure by adding crystalline nano cellulose (CNC) to the cross linking reaction. We expected that the new lignin-cellulose-resilin biocomposite will help better understand the integration of resilin to the plant cell wall. Moreover, such a novel polymer, that combines both strength and elasticity, will be utilized in the future for different industrial applications.


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COMPOSITE HYDROGELS WITH CELLULOSE NANOFIBRILS

ELLINOR B. HEGGSETa, OLAV AARSTADb, INA S. PEDERSENb, BERIT L. STRANDb AND KRISTIN SYVERUDa

aPaper and Fibre Research Institute, Høgskoleringen 6b, 7491 Trondheim, Norway bDepartment of Biotechnology, Norwegian University of Science and Technology,

Sem Sælands vei 6, 7491 Trondheim, Norway [email protected]

ABSTRACT

Composite hydrogels consists of three-dimensional networks, mainly of hydrophilic polymers. In our study we have used cellulose nanofibrils, which are a renewable, sustainable and “green” biomaterial obtained from wood. In combination with other biomaterials (e.g. alginate from marine brown algae), promising composite hydrogels can be produced. Composite hydrogels have many interesting application areas, and can be suggested for use in e.g. medical applications as tissue engineering and drug delivery. Structure-function relationships in the composite hydrogels are of interest, and it is of current interest to see if interactions between different biomaterials give improved hydrogels. Mechanical properties, rheological properties, diffusion properties and swelling / syneresis are relevant parameters in this study.

ACKNOWLEDGEMENT This work has been funded by the Research Council of Norway through the NANO2021 project NORCEL.


47

PREPARATION OF ACTIVATED CARBON FIBERS FROM PHENOLATED BIOMASS WASTES

M. HAKKI ALMAa, TUFAN SALANb

aDepartment of Forest Industry Engineering, Kahramanmaras Sutcu Imam University, 46100, Kahramanmaras, Turkey

bDepartment of Material Science and Engineering, Kahramanmaras Sutcu Imam University, 46100, Kahramanmaras, Turkey


ABSTRACT Activated carbon fibers (ACFs) have superb features due to their developed pore structure, large specific surface area, pore volume, and uniform microporosity and special surface reactivity compared with the common activated carbons. These materials have been greatly used in many areas such as adsorption and separation, catalyst support, electronic materials (Suziki, 1994). ACFs have mainly been produced via carbonization of various fiber precursors, such as rayon, petroleum or coal based pitch, polyacrylonitrile (PAN) and commercial phenol formaldeyde resin etc. (Ryu et al. 1998). However, limited reserves of these resources, the costs of processing and raw material supply, yield, environmental issues etc. bring with a necessity to improve the production of ACFs that highly depends on chemical materials (Kadla et al., 2002). Therefore, to solve these problems, utilization of biomass resources became an important hot issue and many techniques are being developed currently in order to use biomass resources effectively. Recently, wood is almost completely converted into useful liquid chemical raw by liquefaction technique in the phenol, which greatly improves the utilization of wood. Through liquefaction, phenolated (PW) biomass with high reactivity, has been widely used as chemical reagent for production of various materials (Alma, 2008). To expand the usage area of liquefied wood and obtain highly value added products, some scientists studied on carbon fibers and carbon fiber precursors from liquefied wood (Xiaojun and Guangjie, 2007). With exception of wood, some biomass-based ACFs were also produced from renewable sources, such as bamboo, Kenaf, jute, cotton-stalk, etc. become popular as an alternative to petrochemical resources (Ma et al., 2014). On the other hand, in some of the studies, cellulose (Li and Eichhorn, 2006) and lignin (Sudo and Shimizu, 1992) have been used as precursors for ACF production. Cellulose derived ACFs have been firstly developed in the 1950s and 1960s. Then, cellulose became the third largest resource for ACFs after polyacrylonitrile (PAN) and petroleum pitch. However, demand for cellulose derived ACFs reduced because of their low strength and low yield for high-resistance applications comparing with PAN and pitch based carbon fibers (Konkin, 1985; Peng et al., 2003). On the other hand, wood, plenty for cellulose and lignin, has been phenolated for the production of ACFs via liquefaction method. This procedure gives a higher wood utilization percentage and does not require the separation of main components from wood when compared to other


48

techniques (John and Anandjiwala, 2008). There have been several studies on wood-based ACFs. Very recently, Chinese fir sawdust (Lui and Zhao, 2012) and poplar bark (Zhang and Zhang, 2013) have been successively liquefied for the production of ACFs obtained via physical activation method with steam. Although these ACFs had high specific surface area, most of them has a microporous structure with very narrow pore size distribution (PSDs) and they had low yield. This situation represents considerably a barrier for their usage as catalyst supports and capacitors (Ma et al., 2014). Therefore, some scientists used chemical activation method, because it has some advantages over physical activation such as defined micropore size distribution, high yield, pore volume and specific surface area due to reaction with anisotropic carbons to improve large porosity (Krol et al., 2011). Some authors prepared jute based (ACFs) with a porosity of 76.14 by phosphoric acid activation and they investigated the removal of Methylene blue (MB) from aqueous solution. ACFs was successfully employed as an adsorbent for the quantitative removal of MB from aqueous solution (Senthilkumaar et al., 2005).

REFERENCES

[1] Suzuki, M. (1994). Activated carbon fiber: Fundamentals and applications. Carbon, 325, 77-86. [2] Ryu, Z., Zheng, J.T. and Wang, M.Z. (1998). Porous structure of PAN-based activated carbon fibers. Carbon, 36 (301), 427-432. [3] Kadla, J.F., Kubo, S., Venditti, R.A., Gilbert, R.D., Compere, A.L. and Griffith, W. (2002). Lignin-based carbon fibers for composite fiber applications. Carbon, 40, 2913-2920. [4] Alma, M.H. (2008). Determination of the biodegradation of phenolated wood-based molding materials by strength loss method. Holz Als Roh-Und Werkstoff, 66(3), 237-239. [5] Xiaojun. M. and Guangjie, Z. (2007). Preliminary study on preparation of carbon fiber from wood–phenol liquefaction products. Chemistry and Industry of Forest Products, 27(3), 29-32. [6] Ma, X., Zhang, F., Zhu, J., Yu, L. and Liu, X. (2014). Preparation of highly developed mesoporous activated carbon fiber from liquefied wood using wood charcoal as additive and its adsorption of methylene blue from solution, Bioresource Technology, 164, 1-6. [7] Sudo. K. and Shimizu, K. (1992). New carbon fiber from lignin. Journal of Applied Polymer Science, 42, 127-134. [8] Li, N. and Eichhorn, S.J. (2006). Potential stiffness of carbon fibers produced from highly crystalline cellulose. Journal of Materials Science, 41, 4993-4995. [9] Król, M., Gryglewicz, G. and Machnikowski, J. (2011). KOH activation of pitch-derived carbonaceous materials-Effect of carbonization degree. Fuel Processing Technology, 92, 158-165. [10] Senthilkumaar, S., Varadarajab, P.R., Porkodi, K. and Subbhuraam, C.V. (2005). Adsorption of methylene blue onto jute fiber carbon: kinetics and equilibrium studies. Journal of Colloid and Interface Science, 284, 78-82.


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SPECTROSCOPIC AND THERMAL CHARACTERISATION OF THE NEW LIGNIN-BASED MICROSPHERES

M. SOBIESIAKa, B. PODKOŚCIELNAa, B. GAWDZIKa, O. SEVASTYANOVAb,

aDepartment of Polymer Chemistry, Faculty of Chemistry, Maria Curie-Skłodowska University, pl. M. Curie-Skłodowskiej 5, 20-031 Lublin, Poland

bKTH, Royal Institute of Technology, Department of Fibre and Polymer Technology, Division of Wood Chemistry and Pulp Technology, se-10044 Stockholm, Sweden

[email protected]

ABSTRACT Physicochemical properties are important in case of using polymeric microspheres as adsorbents in different chromatographic techniques (GC, HPLC coupled with SPE or SPME). Chemical structure determines kind of possible interaction between surface of an adsorbent and adsorbate molecules, while thermal properties specify the scope of application and possibility of thermal desorption or regeneration of the bed of sorbent.

For these reasons, infrared spectroscopy and thermal analysis are basic techniques used for characterisation of polymeric materials. ATR-FTIR characterise chemical structure and functionalities on the polymer surface. Thermal analysis (TA) allow to define thermal behaviour and stability of a polymeric sample.

In this research, properties of lignin modified styrene-divinylbenzene (St-DVB) microspheres were studied. Kraft lignin (L3) was modified with acrylic acid (LA) and in two steps reaction with epichlorohydrin and acrylic acid (LEA). Suspension emulsion procedure was used to obtained copolymers in microspherical shape. Physicochemical properties of the synthesised polymers were characterised by means of ATR-FTIR and TG-DSC techniques.

Figure 1 presents ATR-FTIR spectra of the monomers - lignin and its acrylic derivatives, and St-DVB-LEA polymer. Unmodified St-DVB was a reference material.


50

4000 3500 3000 2500 2000 1500 1000Wavenumbers cm-1

0.7

0.8

0.9

1

Tra

nsm

itanc

e (%

)

Lignin (L)

LA

LEA

1720 cm-1

1175

4000 3000 2000 1000Wavenumber cm-1

0.96

0.97

0.98

0.99

1

Tra

nsm

itanc

e [%

]

St-DVB

St-DVB-LEA

0.6

0.7

0.8

0.9

1

3358 cm-1

2923 cm-1

2854 cm-1

1727 cm-1

10381180 cm-1

1242 cm-1

2922 cm-1

1600 cm-1

1448 cm-1

1458 cm-1

Figure 1: ATR-FTIR spectra of monomers (left) and St-DVB polymers (right).

In the ATR-FTIR spectra of the lignin chemically modified signals from alcohols and phenols are significantly reduced and signals characteristic for acrylic species are observed (1260, 1175 and 1720cm-1). The St-DVB-LEA polymer possesses numerous functionalities that make its surface more hydrophilic in comparison to that of unmodified St-DVB.

Thermal characteristics of the studied lignin-based polymers is presented in

Table 1 and in figure 2

Table 1: Thermal properties of lignin modified St-DVB microspheres TG DSC

material Tinitial

[ºC] Wloss1

[%] Tmax.

[ºC] Wloss2

[%]

mloss at 800ºC

[%]

Residue at 800ºC

[%]

Tcuring

[ºC] ΔH [J/g]

St-DVB 152 2.8 418 90.6 96.6 4.5 250 9.1 St-DVB-L3 166 0.4 430 91.1 94.8 5.4 294 23.9 St-DVB-LA 163 1.3 425 91.1 95.6 4.6 262 32.2 St-DVB-LEA 242 0.7 421 85.8 89.1 10.8 - -

100 200 300 400 500 600 700 800Temperature [oC]

-20

-16

-12

-8

-4

0

DTG [%

/min]

Lignin

St-DVB

St-DVB-3L

St-DVB-LA

St-DVB-LEA

163oC, 0.23%/min

425oC, 13.9%/min

Figure 2: DTG curves of the lignin and its St-DVB copolymers.


51

The values of initial decomposition temperatures and temperatures of maximum rate of mass loss are a little higher than these for the St-DVB. That means that thermal characteristic of the new lignin-based is better than that of the reference sample. In DSC plots of St-DVB, St-DVB-L3, and St-DVB-LA, curing peak is observed (Table1). Its presence is a consequence of some unreacted double bonds in the polymeric structure. In case of St-DVB-LEA all vinyl groups yield the polymerisation, so the peak was not observed.

The presented results prove that the new lignin-based polymers in form of

microspheres possess hydrophilic functionalities in their surfaces and good thermal stability. These features make them very interesting materials for application in chromatographic techniques.


52

CONTROL OF PROTEIN AFFINITY IN BIOACTIVE NANOCELLULOSE BY PASSIVATION WITH ENGINEERED PDMAEMA-BLOCK-POEGMA

COPOLYMERS AND FALSE POSITIVE RESPONSES

MAIJA VUORILUOTOa, HANNES ORELMAa, LEENA-SISKO JOHANSSONa, BAOLEI ZHUb, MIKKO POUTANENc, ANDREAS WALTHERb,

JANNE LAINEa, ORLANDO J. ROJASa aBiobased Colloids and Materials group (BiCMat), Department of Forest Products Technology, School

of Chemical Technology, Aalto University, FI-00076, Espoo, Finland bDWI – Leibniz Institute for Interactive Materials, D-52056, Aachen, Germany

cMolecular Materials group (MolMat), Department of Applied Physics, School of Science, Aalto University, FI-00076, Espoo, Finland

[email protected]

ABSTRACT Recently, cellulose and cellulosic materials, such as paper and cellulose nanofibril (CNF) films, have been presented as a potential substrate material for diagnostics and various biomedical applications (Pelton 2009, Orelma et al. 2012). Modification of cellulosic surfaces to create anti-fouling properties as well as to control protein adsorption is paramount to the functionality of these kinds of applications. Multifunctional polymers incorporating poly(ethylene glycol) or its derivatives have been found to effectively prevent non-specific protein adsorption on negatively charged and hydrophobic surfaces (VandeVondele et al. 2003, Neff et al. 1998). In this work we present a method to prepare a low-fouling TEMPO-oxidized cellulose nanofibrils (CNF) towards human immunoglobulin G (hIgG) utilizing block-copolymers incorporating poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) . PDMAEMA-b-POEGMA copolymer adsorption on regenerated cellulose, CNF and TEMPO-oxidized CNF films was investigated with quartz crystal microbalance with dissipation (QCM-D) monitoring as well as surface plasmon resonance (SPR) method. Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) were applied to further verify that the adsorption of the block-copolymers was mainly electrostatically driven. The POEGMA-POEGMA block-copolymer adsorbed on TEMPO-CNF surfaces could be partially regenerated in low pH media. In addition, the block-copolymers were observed to be good in preventing non-specific hIgG binding on TEMPO-CNF. The cationic PDMAEMA block of the copolymer functioned as a surface-binding agent to the anionic TEMPO-CNF surface while the POEGMA block provided surface passivating properties. Furthermore, while the functionalized CNF did not bind human IgG it displayed excellent levels of antibody-antigen interactions.


53

REFERENCES [1] Neff J., Caldwell K., Tresco P. (1998). A novel method for surface modification to promote cell attachment to hydrophobic substrates. Journal of Biomedical Materials Research, 40(4), 511-519. [2] Orelma H., Filpponen I., Johansson L-S., Österberg M., Rojas O., Laine J. (2012). Surface functionalized nanofibrillar cellulose (NFC) film as a platform for immunoassays and diagnostics. Biointerphases, 7(1), 1-12. [3] Pelton R. (2009). Bioactive paper provides a low-cost platform for diagnostics. Trends in Analytical Chemistry, 28(8), 925-942. [4] VandeVondele S., Vörös J., Hubbell J.A. (2003). RGD-grafted poly-l-lysine-graft-(polyethylene glycol) copolymers block non-specific protein adsorption while promoting cell adhesion. Biotechnology and Bioengineering, 82(7), 784-790.


54

STRUCTURE EVALUATION OF COMPOSITE MATERIALS BASED ON CNC

MARIA-CRISTINA POPESCU, CARMEN-MIHAELA POPESCU

Petru Poni Institute of Macromolecular Chemistry, Iasi, Romania [email protected]

ABSTRACT

The preparation of high-performance materials from renewable resources has attracted great fundamental and industrial interests in the last years. Lignocellulosics derived from a variety of nature feedstocks (e.g. woods, cotton, and bacterial cellulose) have great potential to replace synthetic (petroleum derived polymers) reinforcements. For this different cellulose forms, like microcrystalline cellulose (MCC), cellulose nanocrystals (CNC) and/or cellulose nanofibrils (CNFs) have been explored as reinforcements for different composite materials (Gu and Catchmark 2013). Poly (vinyl alcohol) (PVA) is a semi-crystalline polymer and water-soluble synthetic polymer with many industrial applications owing to its biodegradability, biocompatibility, chemical resistance, excellent physical properties and gas barrier properties. Even it has been reported that PVA may be completely degraded by bacteria, the degradation rate strongly depends on the residual acetate groups in PVA (Zhang et al. 2014). The PVA/CNC nanocomposites are ideal materials for different applications like: water treatments, packaging films or drug delivery. For this study cellulose nanocrystals (CNC) were prepared by acid hydrolysis and their reinforcement capabilities for poly (vinyl alcohol) (PVA) films were investigated. For the composites preparations three different concentrations of the CNC in the polymer matrix were used. PVA/CNC nanocomposite films were prepared by solvent casting method. The structural features and the differences induced by CNC concentrations and also the interactions between PVA and CNC were investigated by means of infrared spectroscopy

REFERENCES [1] Gu, J., and Catchmark, J.M. (2013). Polylactic acid composites incorporating casein functionalized cellulose nanowhiskers. Journal of Biological Engineering, 7, 31 [2] Zhang, W., He, X., Li, C., Zhang, X., Lu, C., Zhang, X., Deng, Y. (2014) High performance poly (vinyl alcohol)/cellulose nanocrystals nanocomposites manufactured by injection molding. Cellulose, 21, 485–494.


55

GRAFTING OF POLICAPROLACTONE ONTO NANOCELLULOSE OBTAINED BY LIQUEFACTION

M. HUSKIĆa,b, A. ANŽLOVARa, M. KUNAVERa

aNational Institute of Chemistry, Ljubljana, Slovenia. bTecos, Slovenian Tool and Die Development Centre, Celje, Slovenia.

[email protected]

ABSTRACT Nanocrystalline cellulose (NCC) can be obtained by liquefaction of wood, cotton or other sources of cellulose in ethylene glycol using acidic catalysis (Jasiukaityte et al. 2012). Contrary to other types of NCC, it can be dispersed in polar as well as in non-polar organic solvents. Dispersions, in a form of gel, with 10-20 wt.% of NCC in acetone, dioxane, toluene were prepared. Suspensions are suitable for further derivatization and functionalization, as well as direct nanocomposite preparation. Nanocomposites of polycaprolactone (PCL) with 1-3 % NCC were prepared by in situ polymerization of -caprolactone using methylsulfonic acid as initiator. Suspension of NCC (18 wt.%) in dioxane was used as a starting material. Grafting efficiency was determined by extraction. Thermomechanical properties were determined by dynamic mechanical analysis (DMA), degree of crystallinity and crystallization by Dynamic scanning calorimetry (DSC).

ACKNOWLEDGEMENT The authors acknowledge the financial support from the Ministry of Economic development and Technology of the Republic of Slovenia through the contract No. C2130-14-090137 (KROP 13).

REFERENCES [1] Jasiukaityte, E., Kunaver, M., Poljanšek, I., (2012) Influence of cellulose polymerization degree and crystallinity on kinetics of cellulose degradation. Bioresources, 7(3), 3008-3027.


56

FLEXIBILITY OF CELLULOSE NANOCRYSTAL NETWORKS IN RESPONSE TO WATER VAPOR

ELINA NIINIVAARAa, MARCO FAUSTINIb, TEKLA TAMMELINc, HEIKE M.A. EHMANNd,

STEFAN SPIRKd AND EERO KONTTURIa aDepartment of Forest Products Technology, School of Chemical Technology,

Aalto University, Finland bUniversité Pierre et Marie Curie, Laboratorie Chimie de la Matiere Condensée –

Collège de France, France cVtt – Technical Research Center of Finland, High Performance Fibre Products, Finland

dInstitute for Chemistry and Technology, Graz University of Technology, Austria [email protected]

ABSTRACT

Ultrathin films made from renewable resources have become an area of increasing interest for materials scientists as they provide an interesting platform for technological advancements in areas including biosensors, transmitters and optoelectronic materials. For all these types of applications, the predictability of the matrix behaviour to changing atmospheric conditions is essential. In this study, the swelling behavior of cellulose nanocrystal (CNC) thin films has been investigated using ellipsometric porosimetry and quartz crystal microbalance with dissipation (QCM-D). In contrast to what was expected, the results demonstrated that CNC networks supported on a silica substrate showed significant swelling upon the uptake of water vapor. Our measurements clearly establish that thin film CNC networks are responsive to water vapor as they exhibit extensive swelling as a function of relative humidity. CNCs in themselves are not able to swell upon exposure to water vapor as it is unable to penetrate into the crystalline structure thus has no effect on crystal dimensions. So hypothetically, swelling of these films results from flexibility within the nanocrystal network as water vapor is believed to condense in the voids between the CNCs generating capillary pressure that is significant enough to allow movement of the individual CNCs, resulting in the observed swelling.


57

EVALUATION OF SOFTWOOD KRAFT AND ORGANOSOLV LIGNIN AS FEEDSTOCK FOR BIOFUELS AND BIOMATERIALS

OIHANA GORDOBILa*, ROSANA MORIANAb, LIMING ZHANGb,

OLENA SEVASTYANOVAb JALEL LABIDIa aChemical and Environmental Engineering Department, University of the Basque Country,

Donostia-San Sebastián, Spain. bKTH, Royal Institute of Technology, Department of Fibre and Polymer Technology,

Stockholm, Sweden [email protected]

ABSTRACT

Lignin, one of the most important structural components of the lignocellulosic biomass, is an attractive alternative to replace no-renewable sources to obtain energy, fuels, chemicals and materials using a biorefinery process. The structure and properties of lignin biopolymer depends on the origin and on the extraction (or isolation) processes. Lignin is an excellent energy source due to its high heating value (26-28 MJ/ton dry lignin). It is suitable for thermochemical processes, to produce electricity, power, fuel, steam, or syngas. In pulp and paper industries, lignin is used as fuel for the energy production. Also, lignin has an enormous potential as a raw material in the polymer industry. Lignin molecules possess phenolic and aliphatic hydroxyl groups which can be used for chemical modifications.

This study was focused on the isolation of lignin from spruce (softwood) by two different methods, Kraft and organosolv processes. Physico-chemical characterization of obtained samples was performed to assess their potential in either biofuel or biomaterial applications. The properties of isolated lignins are shown in Table 1. The chemical composition of lignins was determined as Klason and soluble lignin in combination with sugar analysis. Elemental analysis was used to determine sulphur content. Size exclusion chromatography (SEC) was used to study the molecular weight distributions. The molecular weight of Kraft Spruce lignin (KS) is significantly higher than Organosolv Spruce lignin (OS). Previously, it has already been shown that Kraft lignins often contain a higher amount of condensed structures than organosolv lignins which can lead to a higher molecular weight. On the other hand, Kraft process generates lignin with highest content of aliphatic and phenolic hydroxyl groups due to the cleavage of α-aryl and β-aryl ether linkages in native lignin molecule (Doherty and Mousavioun, 2011) and high amount of condensed structures that are formed in the last stage of the pulping process (Laurichesse and Avérous, 2014). Regarding thermal properties, the glass transition temperature of lignins is strongly influenced by molecular weight, degree of condensation (number of C-C linkages) and content of phenolic hydroxyl groups. In this case, KS presented the highest Tg due to its high molecular weight and high amount of phenolic OH which restrict the mobility of the molecule by strong intermolecular hydrogen bonding interactions. Also, KS presented higher thermal degradation temperature than OS.


58

Lignins with higher volatile and fixed carbon content are the most appropriate for pyrolysis and combustion processes. For biomaterials applications, in general, relatively high molecular weight with low polidispersity, high purity and high thermal stability are usually required properties. Modifying chemically the aliphatic and phenolic hydroxyl groups of the lignin is possible to elaborate lignin-based polyesters, improve its compatibility with other polymers (such as polyolefines) or elaborated a macromonomer for further copolymerization.

Therefore, the use of chemical modification to create new active sites in lignin, as first step, for further graft polymerization is an attractive alternative to obtain a lignin based copolymers, that can be used in a broader range of applications, and also allow the design of novel materials with special properties and can improve processing characteristics of the lignin (Hilburg et al., 2014).

Table 1. Physicochemical properties of isolated lignins. OS KS

Chemical composition

Klason (%) 94.3 88.5 ASL (%) 3.1 2.3 Ash (%) 3.2 2.5 Total sugars (%) 0.5 1.0 S (%) 0.04 0.22

Molecular weight Mn 1129 1624 Mw 3130 7215 PDI 2.8 4.5

Fuctional groups Aliphatic OH (mmol/g) 0.57 1.64 Phenolic OH (mmol/g) 2.71 3.70 COOH (mmol/g) 0.16 0.3 OCH3 0.68 0.83

Thermal properties Tg 122.7 153.5 T5% (db) 243.2 262 Tmax 382.2 390.7 Char at 800 ºC 46.9 38.8 HHV (MJ/Kg) 24.0 23.0 Volatiles % 55.0 63.9 Fixed carbon % 41.7 33.5

REFERENCES [1] W.O.S. Doherty, P. Mousavioun, C.M. Fellows, Value-adding to cellulosic ethanol: Lignin polymers, Ind Crop Prod. 33 (2011) 259-276. [2] S. Laurichesse, L. Avérous, Chemical modification of lignins: Towards biobased polymers, Prog Polym Sci. 39 (2014) 1266-1290. [3] S.L. Hilburg, A.N. Elder, H. Chung a, R.L. Ferebee,M.R. Bockstaller, N.R. Washburn, A universal route towards thermoplastic lignin composites with improved mechanical properties, Polym. 55 (2014) 995-1003.


59

LIPOXYGENASE FOR OXIDATIVELY DERIVATISING LIGNINS

PAOLA GIANNÌ, HEIKO LANGE, CLAUDIA CRESTINI* Department of Chemical Sciences and Technologies; University of Rome ‘Tor Vergata’;

Via della Ricerca Scientifica; 00133 Rome; Italy [email protected], [email protected]

ABSTRACT

Lignocellulosic biomass can be conveniently be refined using lignocellulosic enzymes; most commonly used are cellulases, laccases and polyphenoloxidases. Enzymatic treatments are, however, are used predominantly during the initial pre-treatment of biomass for easing separation of components, or for funnelling purposes during the production of different fuel classes out of initial degradation products. Numerous studies exist that describe the use lignocellulosic enzymes in biorefinery processes (e.g., Van Dyk et al. 2012). Lignin offers, however, a number of intrinsic functional groups that are not within the target groups for the enzymes mentioned above. Based on studies regarding its mechanism (Zoia et al. 2011) of action, commercially available lipoxygenase (EC 1.13.11.x) could be exploited for structurally modifying lignins. Different conditions can be used for efficiently generating different types of new bonds between lignin oligomers themselves and functional groups alien to lignin.

REFERENCES [1] Lange, H., Giannì, P., Rulli, F., Decina S., Crestini, C. (2015). Manuscript in preparation. [2] Van Dyk, J.S., Pletschke, B.I. (2012). A review of lignocellulose bioconversion using enzymatic hydrolysis and synergistic cooperation between enzymes—Factors affecting enzymes, conversion and synergy. Biotechnology Advances, 30(6), 1458-1480. [3] Zoia, L., Perazzini, R., Crestini, C., Argyropoulos, D.S. (2011). Understanding the radical mechanism of lipoxygenases using 31P NMR spin trapping. Bioorganic & Medicinal Chemistry, 19(9), 3022-3028.


60

CNF IN PAPERMAKING: INFLUENCE ON THE WET-WEB RESISTANCE

AND HANDSHEETS PROPERTIES USING PCC AS FILLER

TIAGO F. NUNES, ANA F. LOURENÇO, JOSÉ A. F. GAMELAS, PAULO J. FERREIRA* CIEPQPF, Department of Chemical Engineering, University of Coimbra,

Pólo II, R. Sílvio Lima, P-3030 790 Coimbra, Portugal [email protected]

ABSTRACT

In a global and very competitive market, the demand for excellence and reduced costs in the pulp and paper industry is permanent and always increasing. The use of higher amounts of mineral fillers in the paper structure partially contributes to reduce costs but it has a negative effect in the mechanical resistances of paper (Lourenço et al. 2014, Hubbe 2014). Another challenge is related to the increasing use of short fibres and their detrimental effect in the wet-web resistance and thus in the runnability. In the last years the interest for cellulose nanofibres (CNF) has augmented exponentially mainly due to their high stiffness and specific surface area which make them especially suited as reinforcement material in different matrices (Zimmermann et al. 2010). The present work has two objectives. On the one hand, it aims at evaluating the contribution of CNF to the increase of the filler content in paper. For that, handsheets were produced with precipitated calcium carbonate (PCC), CNF and retention and sizing agents, and the corresponding structural, mechanical and optical properties were assessed, as well as the filler retention and the drainability of the suspensions. The results are shown in Table 1. On the other hand, this study aims also at evaluating the influence of the CNF on the wet-web resistance of short fibres based papers. The results are plotted in Figure 1. To complement the study and assess the impact of the CNF in the fibrous matrix structure, the handsheets porosity was measured by mercury intrusion. The CNF was produced from an eucalyptus bleached kraft pulp and prepared by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical) mediated oxidation, NaClO and NaBr, according to the methodology described by Saito et al (2007). After the chemical treatment the fibres were subjected to mechanical treatment at a homogenizer. Table 1. Handsheets properties

Sample Retention %

Drainability, s

Tensile Index, N·m/g

Air Permeability (Gurley), s/100 mL

30% PCC–0% CNF 85,8 7,6 23,1 4,0 30% PCC–3% CNF 90,9 17,5 31,1 21,6


61

Figure 1. Wet-web resistance of produced handsheets.

ACKNOWLEDGMENTS

The authors acknowledge QREN (Quadro de Referência Estratégico Nacional) for financial support (QREN 34169 NMC) and RAIZ (Instituto de Investigação da Floresta e do Papel) for the laboratory facilities and some furnish components.

REFERENCES

[1] Lourenço, A.F., Gamelas, J.A.F. and Ferreira, P.J. (2014). Increase of the filler content in papermaking by using a silica-coated PCC filler. Nordic Pulp & Paper Research Journal, 29 (2), 242-247. [2] Hubbe, M. (2014). Prospects for Maintaining Strength of Paper and Paperboard Products While Using Less Forest Resources: A Review. Bioresources, 9(1), 1634-1763. [3] Saito, T., Kimura, S., Nishiyama, Y., Isogai, A. (2007). Cellulose Nanofibers Prepared by TEMPO-Mediated Oxidation of Native Cellulose. Biomacromolecules, 8, 2485-2491. [4] Zimmermann, T., Bordeanu, N., Strub, E. (2010). Properties of nanofibrillated cellulose from different raw materials and its reinforcement potencial. Carbohydrate Polymers, 79, 1086-1093.


62

WHITE WATER RECIRCULATION IN HANDSHEET FORMING AS A MEANS TO EVALUATE FINES PROPERTIES

RAFAEL GINER TOVAR, WOLFGANG JOHANN FISCHER, RENE ECKHART,

WOLFGANG BAUER Graz University of Technology, Institute of Paper, Pulp and Fibre Technology

[email protected]

ABSTRACT Among the different components and fractions involved in the pulp and paper industries and related processes, fines have been lately drawing attention. The effect of fines during paper formation as well as the impact on sheet properties has been widely analysed. Fines are considered by definition as the fraction of pulp which passes through a 200-mesh screen of a fibre length classifier according to the TAPPI Test Method T 261 Cm-94. This category can be divided into fines from mechanical and fines from chemical pulps. Mechanical pulps contain a larger amount of fines (20 to 35% by weight) which have a special character giving high opacity and reasonable strength. On the other hand, chemical pulps contain less fines in a virgin pulp compared to the mechanical pulps. The fines content is in the range of a few percent up to 10-12% depending on the refining level (¡Error! No se encuentra el origen de la referencia.). Chemical pulp fines are further divided into primary and secondary fines. They are similar in size, but their effect on parameters like dewatering, mechanical properties and many more differ. Primary fines are present after the pulping process and consist mainly of parts from the middle lamellae, ray and parenchyma cells and fibre debris and do show a higher extractives and lignin content than the whole pulp (¡Error! No se encuentra el origen de la referencia.). Secondary fines are produced during refining due to shear forces on the fibres surfaces and are usually of a more fibrillar nature. Secondary fines bring fibres into closer contact and enhance fibre-fibre bonding (¡Error! No se encuentra el origen de la referencia., Sirviö 2002), and therefore lead to a stronger increase in tensile strength compared to primary fines (¡Error! No se encuentra el origen de la referencia.). These above mentioned studies demonstrate the relevance of research work on different fines and their properties in sheets. To study these effects, a constant/defined amount of fines retained in laboratory sheet forming is a necessity. Among several options mentioned in the literature white water circulation seems to be the most promising. The white water circulation system in a handsheet former recirculates the fines not retained in the handsheet. After some handsheets are formed and discarded, the system reaches a steady state of constant amount of fines in every sheet. A method that easily indicates whether the amount of fines in the handsheets has reached this “steady state” is of great importance. Once this is accomplished, the handsheet properties can be evaluated. Different studies regarding fines retention using a white water circulation system were already carried out. In experiments performed by Bäckström et al. they tried to achieve


63

a constant amount of fines by producing 10 handsheets, which were discarded before sheets for mechanical testing were formed ¡Error! No se encuentra el origen de la referencia.). In the study conducted by Lindqvist, the method chosen is the one suggested by the Scandinavian Pulp, Paper and Board Committee (SCAN-CM 64:00) , which also uses a white circulation system, and links the amount of fines present on the handsheet with the dewatering time. The dewatering time must in this case remain constant even when additional sheets are prepared (¡Error! No se encuentra el origen de la referencia.). In this study, it was intended to develop a method that ensures a constant amount of fines in every handsheet formed with the least possible effort, as well as an easy and reliable determination of the fines content. To improve the fines retention in the handsheets and thereby reduce the time required to achieve a constant amount of fines, three different meshes were evaluated, i.e., 200-mesh (pore size 1.19 mm), 325-mesh (pore size 44 µm) and 500-mesh (pore size 25 µm). A Rapid-Köthen sheet former equipped with a white water circulation system was used to produce handsheets with a grammage of 60 g/ m2 .The amount of fines retained in each handsheet formed was determined by means of L&W Fibre Tester Plus (fines content based on morphological characterization). In this case, the fines content was defined as the arithmetic content of particles with a length smaller than 200 µm. The fines content in every handsheet formed was determined after each single test. It was possible to achieve a constant amount of fines after some handsheets were disposed. The number of handsheets needed to achieve a constant amount of fines depended on the mesh used. A higher amount of handsheets was discarded for the 200-mesh in comparison with the 325-mesh and the 500-mesh. The highest fines retention was achieved with the 500-mesh, although sheets of some of the evaluated pulp samples could no longer be detached from the mesh without destruction, presumably due to high capillary forces.

REFERENCES

[1] M. Bäckström, M.-C. Kolar, and M. Htun. (2008) Characterisation of fines from unbleached kraft pulps and their impact on sheet properties. Holzforschung, 62(5):546–552 [2] H. Lindqvist, K. Salminen, J. Kataja-aho, E. Retulainen, P. Fardim, and A. Sundberg. (2012) The effect of fibre properties, fines content and surfactant addition on dewatering, wet and dry web properties. Nordic Pulp and Paper Research Journal, 27(1):104–111 [3] L. Paavilainen. (1992)The possibilty of fractionating softwood sulfate pulp according to cell wall thickness. Appita Journal, 45(5):319–326 R.S. Seth. (2003) The measurement and significance of fines. Pulp and Paper Canada, 104(2):41–44 [4] J. Sirviö, I. Nurminen, and K. Niskanen (2003) A method for assessing the consolidating effect of fines on the structure of paper. pages 187–192 [5] J. Sirviö. K. Niskanen. (2002) Fibres and bonds. Fapet Oy, Jyväskylä, 2nd edition edition. [6] Y. Xu and R. Pelton. (2005) A new look at how fines influence the strength of filled papers. Journal of Pulp and Paper Science, 31(3):147–152.


64

CHANGES ON LIGNIN STRUCTURE INFLUENCED BY THE IONIC LIQUID

RAQUEL PRADOa, XABIER ERDOCIAb, JALEL LABIDIb, TOM WELTONa aDepartment of Chemistry, Iimperial College London, UK

bChemical and Environmental Engineering Department, University of the Basque Country, San Sebastián, Spain

[email protected]

ABSTRACT Due to the constantly increase of society dependence on fossil fuels and their inevitable depletion, it is important the development of new technologies for the obtaining of chemicals from other sources with special interest centred in renewable sources. In addition, these technologies should be directed to limit the climate change. Lignin is a phenolic polymer built up by oxidative coupling of three major C6-C3 (phenylpropanoid) units, namely, syringyl alcohol, guaiacyl alcohol and p-coumaryl alcohol, which form a randomized structure in a three dimensional network inside the cell wall (García, 2009). In chemical pulping processes, around 100 million tons per year lignin arises as a byproduct, most of which is burned to generate energy and to recover inorganic chemicals. Only a very small fraction of the lignin (ca. 1.2%) is utilized as material in industrial processes. It is necessary to purify lignin obtained by traditional methods, in order to obtain revalorized products. Due to its aromatic structure, lignin offers several applications. Therefore, there is an increasing demand for new processes that could provide new ways to use this resource in a more efficient manner, not only as fuel but also as starting material for chemical industry with the aim of producing commodity and fine chemicals (Kilpeläinen, 2007). Lignin as the main renewable source of aromatic compounds in the earth and ionic liquids as new generation green solvents, are the perfect combination for the obtaining of phenol derived chemicals, in a greener way, avoiding the use of organic solvents and reducing the atmosphere gas emission since the ionic liquids have very low vapour pressures. The ionic liquids also give the possibility of being reutilized, so the residue amounts is also reduced (Finch, 2012) (Wasserchied, 2009). Lignin structure depends on the lignin source and the extraction method, the study of its structure it is important in order to determine its final application, so that in this work, lignin extracted by different ionic liquids was characterized by spectroscopy and chromatographic methods in order to analyse its structure to determine for which application will be more suitable. The influence of the pre-treatment conditions was also studied. It was observe that the S/G ratio, changed and the presence of different phenol derived groups by py-GCMS.


65

REFERENCES [1] Finch, K.B.H., Richards, R. M., Richel, A., Medvedovici, A.V., Gheorghe, N. G., Verziu, M., Coman, S. M. and Parvulescu, V.I. (2012). Catalytic hydroprocesing of lignin under thermal and ultrasound conditions. Catalysis Today, 196, 3-10. [2] García, A., Toledano, A., Serrano, L., Egüés, I., González, M., Martín, F. and Labidi, J. 2009. Characterization of lignins obtained by selective precipitation. Separation and purification technology, 68, 193–198. [3] Kilpeläinen, I., Xie, H., King, A., Granstrom, M., Heikkinen, S., Argylopuolos, D.S., 2007. Disolution of wood in Ionic liquids. Journal of agricultural and food chemistry.. 55, 9142-9148 [4] Wasserchied, P., Stark. A., 2009. Ionic liquids Handbook of Green Chemistry. Weinheim: Wiley-VCH.


66

CELLULOSE SUBMONOLAYERS

REETA SALMINEN AND EERO KONTTURI, Department of Forest Products Technology, School of Chemical Technology,

Aalto University, Finland [email protected]

ABSTRACT

Submonolayers from cellulose nanocrystals (CNCs) provide an excellent setup for focusing on single crystals and the effects of different environments on their morphology. In addition precise manipulation of the 2D morphology and chemistry of CNCs may lead to their utilisation in new functional materials based on 2D patterns. The submonolayers in this study were simply formed by spin coating from low concentrations of CNC dispersions on cationized substrates. The substrates were cationized to prevent the 2D aggregation of the anionic CNCs. The treatment also enhanced CNC adsorption on the surface, hence the concentration of the cellulose nanocrystal dispersion could be decreased to as low as 5 mg dm-3. The separate cellulose nanocrystals were still uniformly distributed over the sample surface (Figure 1). (3-Aminopropyl)triethoxysilane was found to be the most efficient of the cations tested. The surfaces were exposed to concentrated aqueous hydrochloric acid, hydrochloric acid vapour, and water and the subsequent rearrangements in the 2D morphology of the CNC assemblies were investigated. Furthermore, the necessity of the initial oven curing of the submonolayers on the rearrangements was also scrutinized. The study serves as the first step in the fundamental understanding of robust manipulation of 2D submonolayer patterns from CNCs.

Figure 1. 3 x 3 um AFM height images of cellulose nanocrystal a) 50 mg dm-3 b) 25 mg dm-3 c) 10 mg dm-3 d) 5 mg dm-3 dispersions spin coated on (3-aminopropyl)triethoxysilane.

a)

c) d)

b)


67

POLYELECTROLYTE COMPLEX AND LAYER BY LAYER TECHNIQUE OF STARCHES

SEDAT ONDARALa, MEHMET EMIN ERGÜNa, GÜLIZ HOCAOĞLUa,

EVREN ERSOY KALYONCUb

aKaradeniz Technical University, Faculty of Forestry, Forest Product Engineering, Dep. Pulp Paper Technology 61080 Trabzon, Turkey

b Arsin Vocational School of Higher Education, Karadeniz Technical University, 61090 Arsin, Trabzon, Turkey

[email protected]

ABSTRACT Biopolyelectrolyte complexes (BPEC) and layer by layer (LbL) techniques based on use of cationic and anionic starches were studied regarding their adsorption properties and effects on paper strength properties. Results showed that adsorbed amount of cationic and anionic starches, added sequentially to the fibre suspension, increased to 28 mg/g when addition of total starch reached to 50 mg/g. This was higher than the adsorbed amounts of both BPEC and single addition of cationic starch. The adsorbed amount of starches on silicon oxide surface during building up layers was significantly higher and this resulted in thicker multilayer, which was of relatively lower viscosity and lower shear modulus according to Quartz Crystal Microbalance with Dissipation (QCM-D) experiments. However, the BPEC consisting of cationic and anionic starches lead to thinner layer on the silicon oxide surface and their effects on both tensile and burst indexes were found higher compared to those of the LbL of oppositely charged starches and also mono layer of starch. The experiments findings give indications that higher starch adsorption on fibre enhances paper strength properties but conformation on surface is much more important as it was found for the BPEC application.

Figure 1. Tensile index of paper as a function of starch addition.


68

LIQUEFACTION OF WOOD AND ITS APPLICATION FOR THE PRODUCTION OF THERMOSETTING MOLDING MATERIALS

TUFAN SALANa, M. HAKKI ALMAb

aDepartment of Material Science and Engineering, Kahramanmaras Sutcu Imam University, 46100, Kahramanmaras, Turkey

bDepartment of Forest Industry Engineering, Kahramanmaras Sutcu Imam University, 46100, Kahramanmaras, Turkey

[email protected]

ABSTRACT

Solvolysis liquefaction one of the thermochemical method dissolves wood in an organic solvent with an acidic (e.g. hydrochloric, sulfuric, phosphoric acid) or alkaline (e.g. NaOH, MgSO4) catalyst at moderate temperatures (80-150 ºC) or without catalyst at elevated temperatures (240-270 ºC) and atmospheric pressure (Alma, 1996). Different organic solvents such as phenol (Alma, 2008) and polyhydric alcohols (i.g. ethylene glycol, glycerol, polyethylene glycol) (Kobayashi et al., 2004), have been used for solvolysis liquefaction of wood or its components. The wood naturally comprise polymers such as cellulose, hemicellulose, and lignin which has plenty hydroxyl groups. Hydroxyl groups make it possible to convert liquefied biomass into biopolymers. It can be liquefied in an acidic environment in the presence of above mentioned solvents for the production of bio-polyols. The pasty solutions rich with polyols obtained after liquefaction of wood, have been applied for the preparation of novolak and resol type phenolic resins/moldings/adhesives (Alma et al, 2002), polyurethane foams (Alma and Shiraishi, 1998), carbon fibers (Xiaojun and Guangjie, 2010), polyesters (Kunaver et al., 2010) and epoxy resins (Kishi and Fujita, 2008). With the increasing impetus for a more extensive utilization of the abundant and renewable biomass resources, liquefaction of wood in the presence of phenol and its application to thermosetting materials is a promising technique (Pan et al., 2009). During liquefaction (phenolation), carbohydrate and lignin content of biomass converted to small fragments or monomolecular compounds via hydrolysis, degradation, and decomposition reactions and after this, they react with phenol to form derivatives (Lee et al. 2012). These phenol-liquefied products can easily react with formaldehyde to form novalac or resol type phenol-formaldehyde resins. Also, formaldehyde does not react only with free phenol but also with liquefied wood components having reactive sites. Novolac type liquefied wood resins could be directly synthesized from the co-condensation of liquefied wood and formaldehyde with a phenol-to-formaldehyde molar ratio greater than one under acidic conditions. The viscosity and the flow temperature of liquefied wood-phenol-formaldehyde resins were found much lower than pure liquefied wood (Lin et al. 1995). The mechanical properties of compression molded products from liquefied wood based phenol-formaldehyde resin were comparable to that of the commercial conventional novolac


69

resin. Novolak resins produced from the liquefied wood can be extensively used as molding materials in electrical, automotive, radio and television, and appliance parts just the same as commercial novolak resin-type moldings (Alma and Kelley 2000). On the other hand, resol type phenolic resin is synthesized with a phenol to formaldehyde molar ratio less than one under basic conditions. It has been known that, in the presence of phenol at 250 °C, cellulose and hemicellulose undergo transglycosylation to form (hydroxymethyl) furfural compound in high yield. This formed furfural has been postulated to condense with phenol and formaldehyde through a methylene bridge when resol was produced (Alma et al. 2001).

REFERENCES [1] Alma, M.H. (1996). Several acids-catalyzed phenolation of wood and its application to molding materials. Ph.D. Thesis. Kyoto University, Kyoto, Japan. 135 p. [2] Alma, M.H. and Shiraishi, N. (1998). Preparation of polyurethane-like foams from NaOH catalyzed liquefied wood. Holz als Roh- und Werkstoff, 56, 245-246. [3] Alma, M.H., Basturk, M.A. and Shiraishi. N. (2001). Cocondensation of NaOH-catalyzed liquefied wood wastes, phenol and formaldehyde for the production of resol-type adhesives. Industrial & Engineering Chemistry Research, 40, 5036-5039. [4] Alma, M.H., Kelley S.S. and Bektas, I. (2000). The tensile properties of molding products obtained by the condensation of various tree barks and phenol by using sulfuric acid as a catalyst. Journal of Materials Science Letters, 19, 1517-1520. [5] Alma, M.H. (2008). Determination of the biodegradation of phenolated wood-based molding materials by strength loss method. Holz als Roh- und Werkstoff, 66, 237-239. [6] Alma, M.H., Maldas D. and Shiraishi, N. (2002). Resinification of NaOH-catalyzed phenolated wood–phenol mixture with formalin for making molding materials. Journal of Adhesion Science and Technology, 16(8), 1141-1151. [7] Kishi, H. and Akira, F. (2008). Wood-based epoxy resins and the ramie fiber reinforced composites. Environmental Engineering and Management Journal, 7(5), 517-523. [8] Kobayashi, M., Asano, T., Kajiyama, M. and Tomita B., (2004). Analysis on residue formation during wood liquefaction with polyhydric alcohol. Journal of Wood Science, 50, 407-414. [9] Kunaver, M., Jasiukaityte, E., Cukand N. and Guthrie, J.T. (2010). Liquefaction of wood; synthesis and characterization of liquefied wood polyester derivatives. Journal of Applied Polymer Science, 115, 1265-1271. [10] Li, G-Y., Hse, C-Y. and Qin, T-F. (2012). Preparation and characterization of novolak phenolformaldehyde resin from liquefied brown-rotted wood. Journal of Applied Polymer Science, 125, 3142-3147. [11] Lin, L., Yoshioka, M., Yao, Y. and Shiraishi, N. (1995). Preparation and properties of phenolated wood/phenol/formaldehyde cocondensed resin. Journal of Applied Polymer Science, 58, 1297-1304. [12] Pan H., Shupe, T.F., Hse, C-H. (2009). Characterization of novolac type liquefied wood/phenol/formaldehyde (LWPF) resin. European Journal of Wood and Wood Products, 67, 427–437. [13] Xiaojun, M. and Guangjie, Z. (2010). Preparation of carbon fibers from liquefied wood. Wood Science and Technology, 44, 3-11.

AUTHOR INDEX

COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015

Author Index

70

A

K

Alma, M. H. [email protected]

47,68 Kallio, P. [email protected]

17

Argyropoulos, D. [email protected]

5 Kowaluk, G. [email protected]

33

B

Kutzke, H. [email protected]

12

Batzorka, E. [email protected]

24 L

Bauer, W. [email protected]

17,62 Lange, H. [email protected]

24,43,59

Bock, H. [email protected]

42 M

C

Morais de Carvalho, D. [email protected]

35

Chabbert, B. [email protected]

29 N

Colodette, J. [email protected]

35 Niinivaara, E. [email protected]

56

Crestini, C. [email protected]

24,43,59 O

Czubak, E. [email protected]

33 Ondaral, S. [email protected]

41,67

D

Orelma, H. [email protected]

27,52

Daniel, G. [email protected]

37 P

Dizbite, T. [email protected]

39 Peresin, M. S. [email protected]

21

F

Pesquet, E. [email protected]

6

Fernando, D. [email protected]

37 Podkoscielna, B. [email protected]

31,49

Ferreira, J. [email protected]

60 Popescu, M. C. [email protected]

11,44,54

Filpponen, I. [email protected]

14,15,27 Prado, R. [email protected]

64

G

Preis, I. [email protected]

45

Gianni, P. [email protected]

59 R

Giner, R. [email protected]

62 Raschip, I. [email protected]

44

Gordobil, O. [email protected]

57 Rojas, O. [email protected]

14,15,2021,27,52

Gravitis, J. [email protected]

9 S

Guo, J. [email protected]

15 Salan, T. [email protected]

47,68

H

Salminen, R. [email protected]

66

Hocaoglu, G. [email protected]

41,67 Sevastyanova, O. [email protected]

35,49,57

Huskic, M. [email protected]

55 Sobiesiak, M. [email protected]

49

J

Syverud, K. [email protected]

46

Jajcinovic, M. [email protected]

17

COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015

Author Index

71

T Tejado, A. [email protected]

7

Trifol, J. [email protected]

16

V

Van De Ven, T. [email protected]

7

W

Wilson, B. [email protected]

22

Z

Zikeli, F. [email protected]

25

Documents

Program and Book of€¦ · COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015 SCIENTIFIC PROGRAM 5 27th of May 2015 08:30 - 09:00 Registration and Reimbursement Forms collection. 09:00