Organic Chemistry with Cellulose - STEP ITNstepitn.eu/wp-content/uploads/2009/10/pm12_FSU_Jena...1 Thuringian Institute of Textile and Plastics Research Rudolstadt Dr. Frank Meister

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Thuringian Institute of Textile and Plastics Research RudolstadtDr. Frank MeisterE-mail: [email protected]

Organic Chemistry with Cellulose

Friedrich Schiller University of JenaCenter of Excellence forPolysaccharide ResearchProf. Dr. Thomas HeinzeE-mail: [email protected]

Basic financial support 2002-2008

Th. Heinze • Friedrich Schiller University of Jena

-Structure of cellulose-Chemical modification of cellulose:Type of functional group, Number of functional groups(Degree of substitution, DS), and functionalization pattern, Molar mass and molar mass distribution, Purity

2


Hydrogen bond donator

Hydrogen bond acceptor

(Remember the unusual high boiling point of water)

Most probable hydrogen bond pattern of cellulose I(Kolpak and Blackwell, 1976; 1978)

3


Crystallite CrystalliteAmorphous

region

Schematic plot of the supramolecular structure of celluloseA. Fringed micelleB. Fringed fibrilCrystallites are marked white and amorphous regions are marked black

4


Chemical modification of cellulose: The homogeneousversus the heterogeneous reaction path

Homogeneous reaction means to dissolve the biopolymer prior the chemicalreaction either in non-derivatizing- or derivatizing solvents. In case of derivatizing solvents, not only a conversion of the soluble intermediateformed during dissolution but also the modification of the isolated intermediate,which is re-dissolved in an organic solvent (DMSO, DMF) is considered as homogeneous reaction.

Chemical modification of soluble but “stable” cellulose derivativeslike cellulose acetate in DMSO and of cellulose under dissolutionof the cellulose derivative formed, as a result of the conversion,is not included in the context of homogeneous phase chemistry.

5


CELLULOSE ESTERS

Commercial acylation is exclusively carried out under heterogeneous conditions

OOH

OOH

HO

O

CH3 O CH3

O

OO

OO

O

CH3O

CH3OCH3

O(CH3COOH)Catalyste.g. H2SO4

-10–40% excess to the amount needed for cellulose triacetate formation- DS ~ 3 soluble in CHCl3, e.g.- DS < 3 – products are partly soluble or even insoluble

6


Cellulose fibers and their structure

7


Solubility (- insoluble, + soluble) of cellulose acetate- obtained by hydrolysis of cellulose triacetate -

Cellulose acetate

Solvent

DS Chloro-form

Acetone 2-Methoxy-ethanol

Water

2.8-3.0 + – – –2.2-2.7 – + – –

1.2-1.8 – – + –0.6-0.9 – – – +

8


Cross-section of cellulose acetate filaments, filter tow (light microscope)

Rhodia Acetow Freiburg, Germany

9


Characteristics and application areas of commercially produced organic esters of cellulose

Cellulose Degree of Content of (wt%) Degree of Typical applications

ester polymerization Acetic acid

Propionic acid/ butyric acid/ phthalic acid

Substitution

Triacetate 150-360 60.0-61.4 -/-/- 2.8-2.0 Coatings, LCD displays, photographic films, isolation foils

Cellulose-2,5-acetate

100-200 55.0-55.5 -/-/- ~2.4 Textile fiber (artificial silk), molding plastics, coatings lacquers, filter tow, thermoplastics

Acetopropionate 150-200 5 57/-/- 0.3-2.3 Thermoplastic compounds

Acetobutyrate 100-150 43 -/18/- 2.1-0.6 Isolated lacquer raw materials, foils

40 -/22/- 2.0-0.7 Foils, films

20 -/44/- 1.0-1.6 Thermoplastic compounds

9 -/59/- 2.0 0.5-2.3 Melt dip resins

Acetophthalate 150-200 24 -/-/35 0.8/1.6 Coatings, enteric coatings, pharmaceuticals

10


Comments about the characterization

of cellulose esters

11


5 4 3 2

H-2H-3 H-1, 6

H-6'H-4

H-5

Acetyl-CH3

6 2 3

ppm

OO

OO

O CH3

CH3

O

O

O CH3

123

4 56

1H NMR spectrum of a cellulose triacetate

0 .51 .0

1.01 .52 .0

2.02 .53 .0

3.03 .54 .0

4.04 .55 .0

5.05 .56 .0

ppm

Modified RU

CH3(acetate)

HODDMSO-d6

ORO

ORO

OR

R= CH3(C=O) or H according to DS

1H NMR spectrum of a cellulose acetate (DS 2.37)

12


Determination of degree of substitution and substitution pattern of cellulose estersafter peracetylation and 1H NMR spectroscopy

2.20 2.00 1.80 2.20 2.00 1.80

Acetyl-CH3

2

3

6

ppm

A) B)

1H NMR spectra of a cellulose acetate A) before and B) after deuteroacetylation

13


5.0 4.5 4.0 3.5

5.0

4.5

4.0

3.5

H-3 H-2

H-1 H-6

H-6' H-4 H-5

3 2 14ppm

H-3H-2

H-1, 6

H-6' H-4H-5

Propionyl-CH2

Acetyl-CH2

23

6

Propio-nyl-CH3

6 2, 3

ppm

OO

OO

O CH3

CH2CH3

O

O

O CH3

123

4 56

AGU,H

opionylPr,HAcyl H3

I73DS

⋅

⋅−=

AGU,H

opionylPr,HAcyl I3

)n(I71)n(DS

⋅

⋅−=

I= Integral

n= Position 2, 3, or 6

14

1H NMR spectrum (left) and 1H,1H-COSY NMR spectrum (right, the area of the protons of the AGU is displayed)of cellulose acetate propionate prepared by complete propionylation of a commercial cellulose diacetate(CDCl3, 32 scans)


Determination of degree of substitution and substitution pattern of cellulose esters after peracetylation and 1H NMR spectroscopy

15

)(3)(7

AGUIntegralCHLauratIntegralDSEster ∗

−∗= 3

1H NMR spectrum of a peracetylated cellulose laurate (DSLau= 1,52) in CDCl3 at 40°C (16 scans).


Solvents for cellulose

16


Solvents for Cellulose

Indispensable prerequisite for

i) SHAPINGe.g., fiber spinning applying- N-methylmorpholine-N-oxide monohydrate- CS2/NaOH/H2O

NMNO fiber Viscose fiberTEM of fiber cross-section (Fink et al., 2001)

Viscose- versus NMNO fibers

Structural comparison NMNO 1st generation Viscose (normal)

Cross section shape Round/Oval LobateCross section morphology Homogeneous, dense Core/SkinCrystallinity High Variable

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Light scattering, Zimm plot of linters in Cd-tren*Burchard et al., Macromolecules 33 (2000) 4094.

*tren = tris-2-aminoethylamine


ii) CHARACTERIZATIONe.g. determination of molar mass and molar mass distribution

[ ])1(1

/)1(−⋅+

−=

reln

rel

Kc

ηηη

Cupriethylenediamine (Cuen) DIN 54270

h

M1

M2

18




iii) HOMOGENEOUS CHEMICAL MODIFICATION

O

HOTDMS-O

O

O-TDMS

a

(THF)

O

OTDMS-O

OH3C

b

(THF)

O

OOH

O

OH

H3C

O-TDMS

O

HOOH

O

OH

O

HOO

O

O+ SiCl

Imidazol

(DMA/ LiCl)

Si

Si

TDMS-Cl

19


Non-derivatizing solvents Derivatizing solvents

Aqueous media Non-aqueous media

• Aqueous inorganic complexes • Organic solvent/inorganic salt • CF3COOH/(CF3CO)2O

[Cu(NH3)4](OH)2 - Cuam CH3CON(CH3)2/LiCl • HCOOH

[Cu(H2N-(CH2)2-NH2)2](OH)2 - Cuen (CH3)2-SO/CaCl2 • CS2/NaOH

[Cd(H2N-(CH2)2-NH2)3](OH)2 - Cadoxen (CH3)2-SO/(C4H9)4NF

• Aqueous bases • Organic solvent/amine/SO2

10% NaOH (CH3)2-SO/(C2H5)3N/SO2

• Mineral acids • Ammonia/ammonium salt

H2SO4; H3PO4 NH3/NH4SCN

• Melts of inorganic salt hydrates • Oxides of tertiary amines

LiClO4 x 3 H2O

ZnCl2 x 4 H2O • Ionic liquids

20


13C NMR spectrum of cellulose trifluoroacetate (DS 1.5) in N,N-dimethyl formamide-d7

21

22


C-1C-4

C-5C-3

C-2C-6

ppm 100 90 80 70 60

1. Th. Heinze et al., Macromol. Chem. Phys. 201 (2000) 6272. M.C. Vieira, Th. Heinze, Cellulose 9 (2002) 2033. G.T. Ciacco, E. Frollini, Th. Heinze, Cellulose 10 (2003) 125

13C NMR spectrum of Cellulose (3%, w/w) dissolved in dimethylsulfoxide (DMSO)/tetrabutylammonium fluoride, 50 °C, 9.200 scans (peaks below 57 ppm not shown)

OO

OHHO

OH

12

4 56

3


Novel cellulose solvents:

- Dimethyl sulfoxide/tetrabutylammonium fluoride

- Ionic Liquids

23


Dimethyl sulfoxide/Tetrabutylammonium FluorideTh. Heinze et al., Macromol. Chem. Phys. 201 (2000) 627

DMSO/5-20% Tetrabutylammonium fluoride (TBAF) x 3 H2O

Air-dried cellulose, DP≤650, no pretreatment Cellulose isolated from agave containing 6% hemicellulose xylanAir-dried cellulose from Sisal, DP>650, Activation pretreatment30 min, room temperature, 60 min, 60°C

OOH

OOH

HO123

4

5

6O

OH

OOH

HO123

4

5

6

Solv.

The cellulose dissolves within 15-30 mindepending on DP and concentration

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25Dissolution of cotton fibers visualizedby light microscopy with P. Navard, France

Köhler and Heinze, Macromol. Biosci. 2007, 7,307


DMSOPreparation according toSun and DiMagno, J. Am. Chem. Soc. 2005, 127, 2050

Solvents for Cellulose:Anhydrous Tetrabutylammonium Fluoride (TBAF)/DMSO

Cellulose is soluble in this mixture

FF

FF

F

FN +

(DMSO)RT, 1h

N

CNCN

CNCN

NC

NC+

CN F

Dissolution of cotton fibers visualizedby light microscopy


Chemistry of cellulose dissolved in DMSO/TBAFx3H2OApplying esterification agents that tolerate water

R Mol/mol AGU DS

CH3 1.5 0.63CH3 2.3 1.07CH3 10.0 2.72(CH2)2CH3 2.3 0.86(CH2)10CH3 2.3 1.47(CH2)10CH3 10.0 2.60C6H5 2.3 0.95

Conversion of spruce sulfite pulpwith vinyl carboxylic acids(11%TBAF/DMSO, 40°C for 70 h)

Results are comparable with reactions of cellulosedissolved in DMA/LiCl,however, to dissolve the biopolymer inDMSO/TBAF is simple and fast

26

27

Ionic Liquids as New Solvents for CelluloseFirst described by Swatloski, Spear, Holbrey, Rogers, JACS 2002, 124, 4974,

WO 03/029393 A2

C & EN / November 8, 2004


Definition of ionic liquids (IL)

N N+

R

N - a l k y l - N - m eth y l -i m i d azo l i u m

N

R

+

N - a l k y l -p y r i d i n i u m

R 4

N +

R 3

R 1

R 2

t et r aal k y l -am m o n i um

R 4

P +

R 3

R 1

R 2

t er taal k y l -p h o sp h on i u m

R 1 ,2 ,3 ,4 = C H 3 (C H 2 ) n , ( n = 1 , 3 , 5 , 7 , 9 ...) ; ar y l ;etc .

C at i o n s :

A n i on s : H 2 O - H 2 O -

[ PF 6 ] -

[ B R 1 R 2 R 3 R 4 ] -

[ B F 4 ] -

[ C F 3 SO 3 ] -[ N O 3 ] -

[ C F 3 C O 2] -

B r - , C l - , I -

solubleinsoluble


• Organic salts, melting point under 100°C (sometimes lower, even room temperature).• Non-flammable, highly thermal stability, no measurable vapor pressure• Designer solvents (adapted properties to each problem)

Not really estimated in cellulose chemistry up to now –mainly imidazolium based IL are studied

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IL as solvent for cellulose

- Different type of cellulose; DP in the range from 290 to

6500

- Solubility of the cellulose depends on alkyl chain length

n = 0 not soluble

n = 1, 3, 5 soluble

n = 7 extensive swelling

- No degradation of the polymer (sometimes, conditions)

- Non-derivatizing solvent

Recycling of the IL

- Almost complete, without any impurities (Lab-scale

synthesis).

N N+

H3C

X-+

(CH2)nCH3

29


30

IL used in the studiesN N

+

H3C CH2(CH2)2CH3

Cl -N N

+

H3C CH2CH3

Cl-

1-N-Ethyl-3-methylimidazolium

chloride (EMIMCl) N N+

H3C CH2CH3

Ac -

1-N-Ethyl-3-methylimidazolium

acetate (EMIMAc)N N

+

H3C CH2(CH2)2CH3

Cl-

CH3

1-N-Butyl-2,3-dimethylimidazolium

chloride (BDMIMCl)

N N+

H3C

Cl-

1-N-Allyl-2,3-dimethylimidazolium

chloride (AMIMCl)

1-N-Butyl-3-methylimidazolium

chloride (BMIMCl)

Purity of the IL is a problem, impurities may act as catalystor inhibitor and/or side reactions may occur


DP 350

OHO

OHO

OHO

R'OOR'

O

O R

O

R'=R

OBMIMCl

or H

RCl

O

80°C , 2 h

IL as reaction media: Acylation with acid chloridesD

egre

e of

sub

stitu

tion

0

1

2

3

1/1/2.5 1/3/2.5 1/5/2.5

DS> 0.3soluble in DMSO

DS> 2.0soluble in acetone and chloroform

AGU/Reagent/Pyridine

Pentanoyl chloride Hexanoyl chloride Benzoyl chlorideAcetyl chloride

31T. Heinze, K. Schwikal, S. Barthel, Macromol. Biosci., 2005, 5, 520.

Synthesis of cellulose furoate with furoyl chloride in various IL,(65°C, 3 h, molar ratio of AGU/pyridine/furoyl chloride of 1/3/3)

OHO

OHO

OH

ORO

ORO

OOCl

O OO

BMIMClPyridine65 °C, 3 h

Ionic Liquid DSBMIMCl 2.43EMIMCl 2.21EMIMAc ??

32

O

EMIMAcPyridine65°C, 3 h

EMIMAcPyridine65°C, 3 h

OHO

OHO

OH

ORO

ORO

OOCl

O CH3

O

CH3R= or H

ORO

ORO

O CH3

O

CH3R= or H

H3C S ClO

O O

Ionic Liquids may be reactive leading to unexpected products, here via formation of the mixed anhydride with the cation

S. Köhler, T. Heinze, Cellulose 14 (2007) 489 Th. Heinze, T. Liebert et al., Macromol. Rapid Commun., 28 (2007) 2311

Cellulose sulfation in IL

OO

OH

OHHO

OO

OSO3Na

ORRO

SO3NaR:H

SO3-pyridine

BMIMCl/DMF25°C

Water soluble CS above DS 0.25 !

13C NMR spectrum of cellulose sulfate (DS = 0.87) in D2O, recorded at 70°C60.065.070.075.080.085.090.095.0100.0105.0 ppm

C-1

C-2,3,5

C-4

C-6

C-6sulfated

C-1sulfated at C-2 C-2sulfated

• Homogeneous sulfation / co-solvent improves miscibility • DS controlled via amount of sulfating agent• At 25°C reaction temperature, almost no chain degradation• Cellulose sulfate (CS) with adjustable DS and properties (viscosity of solutions)easily accessible• CS forms polyelectrolyte complexes with polycations

33M. Gericke, T. Liebert, T. Heinze, Macromol. Biosci. 2009, 9, 343

Cellulose sulfation and in-situ formation of polyelectrolyte complexes with water-insoluble CS in IL

4 mm

+

PolyDADMACin water

DS = 0.16, water insolubleEMIMAc

N Cl

n

OOHO

OH

OSO3Na

200 nm

20 µm 100 µm

2 µm

• Water insoluble CS and IL used as solvent• Defined pore structure • Increased mechanical stability

• FTIR and NMR revealed complex formation• Capsules free of IL cation but contain

acetate anions

• Encapsulation of glucose oxidase• Relative enzyme activity (14%) identical

to common PEC capsules

M. Gericke, T. Liebert, T. Heinze J. Am. Chem. Soc. 2009, 131, 1322034

Novel path for the preparation of cellulose esters

ISBN: 3-540-32103-9

Esterification using in situ activation of the carboxylic acids

CO

OCR

O

NN

NN C

O

NN

+ RCOOHN

NH

DMSO/80°C

-

-+

C

O

RN

NO

O

C

-CO2C

O

RN

N

NNH-

+ PS-OH

PS O

R

O

N,N´-Carbonyldiimidazole (CDI) as activating agent is of particular interest for the esterification Mild conditions Products of high degree of substitution Pure products that can be applied in biomedical applications No polymer degradation

Multifunctional polysaccharide esters by one-pot reaction or step-by-step synthesis strategy

T. Liebert & Th. Heinze Biomacromolecules 2005, 6, 333St. Hornig & Th. Heinze Macromolecular Bioscience 2007, 7, 297

35

Examples of polysaccharide esters prepared

36

O

HOOH

OH

OO O

HOOH

OH

O O

HOOH

OH

Cellulose

O

HOOH

OO O

HOO

O O

HOOH

O

HOOH

HOOCO

Xylan

O

HOOH

O

HO

O

O

HOOH

HO

O

O

HOOH

HO

Dextran

NH

OO

Chiral R

OO

Photo-cross-linkable R

OO O

R´s assigned for solubilityS

O

ON3

Reactive R

O

O

O

O

O

O

O

O

O

OO

O

O

Complexing R

Lipophilic polysaccharide derivatives - with a set of funtional groups (R),high degree of substitution (DS) and even complete functionalization

37

How to prepare nanoparticles: Dialysis

Slow exchange of the solvent against the non-solvent water

via a cellulose membran, e.g.

Potential solvents: DMA, DMSO, acetone

Pore size of membrane, change of temperature (10 to 80°C)

and stirring during dialysis have no influence on particle size and

the particle size distribution

1 µm


The homogeneous versus the heterogeneous reaction path

Etherification

Mostly, the solvents do not tolerate reagent like NaOH, NaH to initiate the etherification.

Nevertheless, special structures can be synthesized by etherification starting with the dissolved polymer.

38

39

Carboxymethylcellulose (CMC) - Conventional Products

Synthesis

Completely heterogeneous synthesisDSCM = 0.4... 1.3 (one step synthesis)Water- soluble polyelectrolyteNon- toxicWidespread use

50-700C, 3-6h

Aqueous NaOH/ClCH2COONa



40

Carboxymethylcellulose (CMC)-Conventional Products

Distribution of Carboxymethyl Groups

Statistic content of the 8 O-2 > O-6 > O-3 different repeating units

1H NMR spectrum of CMC (DSCM = 0.45) HPLC analysis of CMC (DSCM = 0.95)after hydrolysis with D2SO4 / D2O after hydrolysis with HClO4

Macromol. Chem. Phys. 195 (1994) 1483 Angew. Makromol. Chem. 215 (1994) 93

H -1ß(O-2u) O-2α O-2ßH-1α (O-2u)

H-1α (O-2s) H-1ß(O-2s) O-3

O-6


Plot of mole fractions versus DS of CMCsprepared by the conventional process

0,0

0,2

0,4

0,6

0,8

1,0 glucosemono CMGdi CMGtri CMG

Mol

e fra

ctio

n

0,0 0,5 1,0 1,5 2,0 2,5 3,041

DSHPLC

42

Carboxymethylcellulose (CMC) - New ProductsAlternative Synthesis

Dissolving the polymer Induced Phase Separation Carboxymethylation(e.g. with solid NaOH particles)

ClCH2COONa

10 - 24h, 700C

DSCM = 0.3... 2.1(one-step synthesis)

Appropriate systems FTIR : 1635, 1410 cm-1

(ν COONa)N,N –dimethyl acetamide / LiClN -methylmorpholine-N-oxide / dimethyl sulfoxidecellulose intermediates (formate, trifluoroacetate,trimethylsilyl ether) in dimethyl sulfoxide

J.M.S.-Pure Appl. Chem. A33 (1996) 613Macromol. Symp. 130 (1996) 271

Polarizing light microscopic characterization


0,0

0,2

0,4

0,6

0,8

1,0

Mol

e fra

ctio

n

DS0,0 0,5 1,0 1,5 2,0 2,5 3,0

DMA/LiClTMSC

CFCTFA

CFCTFA

TMSC

TMSC

CA

glucosemono CMGdi CMGtri CMG

CA: cellulose acetateTMSC: trimethylsilyl celluloseCTFA: cellulose trifluoroacetateCF: cellulose formateDMA/LiCl: solution

Plot of mole fractions versus DS of CMC prepared via induced phase separation

43


44

Carboxymethylcellulose : Enzyme - supported characterization


45

46

Turb

idit y

( ar b

it rar

y un

i ts)

Z eta

po t

entia

l (m

V )

Molar ratio of cationic to anionic groups Volume (µl)

Turbidimetric titration of aqueous CMC Zeta potential measurements of a BaSO4

solutions DSCM = 1.7 with poly(diallyl- suspension dependent on addition of dimethylammoniumchlorid) aqueous CMC (New Product, 0.05%)

Cooperation : H.-J. Kötz, University of Potsdam, Germany

Carboxymethylcellulose (CMC) - New ProductsProperties

Commercial CMCAlternative CMC

47

Carboxymethyl cellulose (300 kt/a)

Methyl- (70 kt/a) and hydroxyalkyl cellulose (54 kt/a)

Ethyl cellulose

Cellulose Ethers – Key Substances in many Applications

Strong interactions by intramolecular- and intermolecular hydrogen bondsActivation of the biopolymer with aqueous NaOH prior the reaction

OO

OHHO

OH

/ Structure

Functionalization Pattern in Cellulose Derivatives

OH

HO

OHHO

HO HOHO

OHOH

OH

OH

OHOH

OHHO

OH

OH

HOOH

OHOH

OH

OH

HOO

OO

OOO

OO O

OO

O OO

OO

OEt

OEtEtO

OEt

OEt

EtOOEt

OEtOEt

OEt

OEt

EtOHPO

OHPOHP

OHP

OHP

HP: HydroxypropylH3C

OHEt: Ethyl CH2CH3

OO

OHHO

OH

OO

OHHO

OEtO

OOEt

HO

OHO

OOH

EtO

OH

OO

OEtHO

OEtO

OOH

EtO

OEtO

OOEt

EtO

OH

OO

OEtEtO

OEt

Repeating units of ethyl cellulose

Ethylhydroxypropyl cellulose

• Up to 27 differently functionalized repeating units may appear considering the reaction at the hydroxyls at the AGU

• Novel OH group of the hydroxypropyl ether (HP) formed may react as well –further increase of number of repeating units

48

Regioselectivity

49

Protecting group technique: Simultaneous protection of position 2 and 6 with bulky silyl reagents

TDMS-ClImidazol

24 h, 100°C(DMA,LiCl)

O

HOOH

O

OHO

HOO

O

O

Si

Si

A. Koschella, Th. Heinze, D. KlemmMacromol. Biosci. 1 (2001) 49.

1

Th. Heinze, A. Pfeifer, K. PetzoldBioResources 3 (2008) 79.

TBS-ClImidazol

OHO

OO

OSi

Si

OR

TBAF

24 h, 50°C

O

OOH

O

OH

R(Organic solvent)

O

HOO

O

O

Si

Si

R-HalNaH

72 h, 50°C(THF)

O

OO

O

O

Si

SiR

50

51

Properties of 3-O-functionalized cellulose ethers: Solubility

Thermoreversible flocculation

Reactive

-+-++

++++++-

Dimethyl sulfoxide

---Propargyl

---Dodecyl

++-Butyl

++-/+Propyl

+-+3’-Hydroxypropyl (X)

+-+Hydroxyethyl (X)

+-+Methoxyethyl (X)

+-+Ethyl (X)

++-iso-Pentyl

---Oligo(Ethylenglycol)

+--Allyl

---Methyl (X)

N,N-Dimethyl acetamide

EthanolWater(20°C)

Sample

Insolubility indicates H-bonds

Thermoreversible flocculation- soluble below 20°C

Reactive

Kadla et al., 2008

(X) – Model compounds of commercially produced cellulose ethers

Properties of 3-O-functionalized cellulose ethers: Thermoreversible flocculation

52

Cellulose ether Flocculation temperature (°C)

Ethyl cellulose ≈303-mono-O-Ethyl cellulose ≈60

3-mono-O-Methoxyethyl cellulose does not show flocculation at all

Regioselectivity

Click Chemistry

53

Click chemistry – a novel approach to unconventional cellulose products

CuSO4 *5 H2O, sodium ascorbate,dimethyl sulfoxide, 24 h, 25°C

OH

NCH3O

O

OCH3

O

N3OO

OHO

OH OO

OHO

N NN

N

O

OCH3

O

OCH3

OHO

OHO

N3N

O

OCH3

O

OCH3

OHO

OHO

N NN

N

O OCH3

O

OCH3

54

Heinze et al., Macromol. Rapid Commun. 27 (2006) 208-213

Click chemistry – a novel approach to unconventional cellulose products

O

O OOHO O

N3

O

OH

O

HO OO

OH

O-Na+O

OO-Na+

O-Na+O

12

3

4 56

OO

O-Na+

78

9

10

11

12 Carboxymethyl-6-deoxy-6-azido cellulose, DSAzide 0.81; DSCM 1.25

55

O

OO OHO O

N3

O

OH

O

HO O

OO

HO

O

O

O

OH

+Na-O OO-Na+O

O O-Na+ O-Na+

O

12

3

4 56

OO-Na+

24

25

26

27

28

29

N

HNNH

O O

NN

O

OO

O

NH

HN NHHN

N

N N

N

OCH3

H3CO

O

O

OCH3OCH3

O

OOCH3 OCH3

O O OCH3O

OCH3

O

N N

N7

8 9

10

1112

13

14 15

1617

18

19 2021

2223

Samples are soluble in waterdue to the additional ionic groups

Dendronization via Click chemistryHomogeneous approach(Water)

Heinze et al., European Polymer Journal 45 (2009) 1098

Click chemistry – a novel approach to unconventional cellulose products – biofunctionalization

OHO O

OH

N

HNNH

O

N N

O

NH

ONH HN

OO

HN

NN

N

NH2 H2N NH2 H2N

OHO O

N3

OHO

CuSO4*5H2O,sodium ascorbate

DSTriazole 0.25

DSAzide 0.75

N

HNNH

O

N N

O

NH

ONH HN

OO

HN

NH2 H2N NH2 H2N

O

+

(DMSO), rt, 24 h

1

2

3

6-deoxy-6-(1,2,3-triazolo)-4-polyamidoamine (PAMAM)cellulose of 2.5th generationobtained by copper-catalyzedHuisgen reaction (Click Chemistry)

563500 3000 2500 2000 1500 1000 500

Wave number [cm-1]

OH

N3 C-O-C

NH2

-NH-CH2

-OCNH-

A

B N3

3500 3000 2500 2000 1500 1000 500

Wave number [cm-1]

OH

N3 C-O-C

NH2

-NH-CH2

-OCNH-

A

B N3

a) Reaction can be carried outat membrane of6-deoxy-6-azido cellulose

ATR/IR spectra of films ofA) deoxy-azido cellulose andB) after surface modification with propargyl-PAMAM dendron of 2.5th generation via copper-catalyzedHuisgen reaction

Heterogeneous approach

A novel type of structure forming polymers: Amino cellulose

Biofunctionalized surfaces with amino cellulose

NH

NH

Bifunctional coupling reagent

NH2

“Biofunction”

Substrate material

Aminocellulose-monolayerSelf-assembling

“Adhesive interactions”

(spacer)

NH2

Bifunctional coupling reagent

57

Click chemistry – a novel approach to unconventional cellulose products – biofunctionalization

NH2 Amount Specific Activity (nmol/cm²) (mU/cm²)

71.34 135.16

58

(Methanol), 3 h, 25°C

Propargyl-PAMAM Dendron (2,5. Gen.) Cu(I)-Katalysator

Glukoseoxidase

NN

NN

NN

NN

N

Glutar-dialdehyd

N

NH HN

O

NNO

HN

OHNNH

O O

NH

NN

N

H2NNH2H2NNH2

O

N3

N3

N

OH

H

N3

N3

GOD

N

NH

H

N3

N3

Dendronisierung

Relative enzyme activity:Arel=Aimmobilized/Adissolved = 27.2%

M. Pohl, N. Michaelis, F. Meister, Th. Heinze, Biomacromolecules 10 (2009) 382

Summary

Organic chemistry with cellulose is one of themost important tools to design novel materialsbased on the most important renewable resourcecellulose.

Organic chemistry is a fascinating work.

59

Acknowledgements

60

PhD- andDiploma Students

Postdocs/Scientific coworkers

Technicians

Scientific coworkers

AcknowledgementsCenter of Electron Microscopy, FSU Jena

Institute of Pharmaceutical Technology, FSU Jena

German Science Foundation

Thank you very much for you kind attention

European Union

Funds of the Chemical Industry of Germany

61

Documents

Organic Chemistry with Cellulose - STEP ITNstepitn.eu/wp-content/uploads/2009/10/pm12_FSU_Jena...1 Thuringian Institute of Textile and Plastics Research Rudolstadt Dr. Frank Meister