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<ul><li><p>lable at ScienceDirect</p><p>Journal of Cleaner Production 142 (2017) 3759e3768</p><p>Contents lists avai</p><p>Journal of Cleaner Production</p><p>journal homepage: www.elsevier .com/locate/ jc lepro</p><p>Potential use of waste paper for the synthesis of cyanoethyl cellulose:A cleaner production approach towards sustainable environmentmanagement</p><p>Gyanesh Joshi a, *, 1, Sanjay Naithani a, V.K. Varshney b, Surendra S. Bisht c, Vikas Rana a</p><p>a Cellulose and Paper Division, Forest Research Institute, Dehradun 248006, Indiab Chemistry Division, Forest Research Institute, Dehradun 248006, Indiac Chemistry of Forest Products Division, Institute of Wood Science &amp; Technology, Bangalore 560003, India</p><p>a r t i c l e i n f o</p><p>Article history:Received 21 February 2016Received in revised form24 September 2016Accepted 18 October 2016Available online 19 October 2016</p><p>Keywords:Waste-paperFunctionalizationCyanoethyl celluloseDegree of substitutionCrystallinityPulp</p><p>* Corresponding author. Uttarakhand Technical UniE-mail address: (G. Jos</p><p>1 Present address: Lecturer (Chemistry), Departmeernment Polytechnic, Kandikhal, Tehri Garhwal, Uttar</p><p> 2016 Elsevier Ltd. All rights reserved.</p><p>a b s t r a c t</p><p>Recycling of waste paper was investigated with the aim of boosting the use of recycled materials andreducing the impact of waste paper on environment. Commercially important cyanoethyl celluloseproduct from waste paper was synthesized successfully through a cycle of chemical treatments. Wastepaper was functionalized to cyanoethyl cellulose in an alkaline heterogeneous reaction environmentwith acrylonitrile under different reaction conditions with respect to degree of substitution. The vari-ables studied were: Sodium Hydroxide and acrylonitrile concentration, reaction time and temperaturefor alkalization and cyanoethylation. All the cyanoethyl cellulose products were assessed for solubility,degree of polymerization and degree of crystallinity. The optimum conditions for cyanoethyl cellulosesynthesis comprised of 8.34 M/anhydro glucose unit aqueous sodium hydroxide concentration, 30 Calkalization temperature, 60 min alkalization time, 70 M/anhydro glucose unit acrylonitrile concentra-tion, 60 min reaction time for cyanoethylation and 50 C cyanoethylation reaction temperature. Theoptimized cyanoethyl cellulose product was characterized with fourier transform infrared spectroscopy,proton magnetic resonance spectroscopy, X-ray diffraction and scanning electron microscopy. Thisinvestigation helped to find the proper cleaner production approach towards sustainable environmentmanagement by synthesizing valuable cyanoethyl cellulose product and demonstrated that waste paperhave the capacity to produce upgraded and high quality cyanoethyl cellulose for variety of applications.</p><p> 2016 Elsevier Ltd. All rights reserved.</p><p>1. Introduction</p><p>Growth of population, increasing urbanization, rising standardsof living due to technological innovations contributed to an in-crease both in quantity and variety of solid wastes generated bydifferent industrial, mining, domestic and agricultural activities.Pulp and plywood industries are two major users of virgin forestresources for cellulosic mass. Other industries are also competitivefor this biomass. This competitiveness leads to higher pressure onresources. Regular negligence towards the reuse or second stageutilization of this mass is further a pressure on environment by theproduction of greenhouse gases on burning during anthropological</p><p>versity, Dehradun, India.hi).nt of Applied Sciences, Gov-akhand, India.</p><p>activities. Among all solid wastes generated, annually severalmillion tons of paper is produced and used worldwide which un-doubtedly gives rise to a huge amount of wastepaper. Huge amountof waste paper, which comes from offices, is currently underutilizedand finally achieve to burning or slow biodegradation. Extraction ofcellulose and production process of a single A4 sheet paper fromfresh cellulosic raw material, through pulping route, is responsiblefor higher carbon foot prints as high as 4.74 g CO2 eq/sheet (Diasand Arroja, 2012). This environmental damage can be overcomeby advocating to check the release of this carbon in atmosphere byreusing or recycling of this paper in development of other cellulosicproducts. The utilization of waste paper for the production of newproducts is increasing all over the world in recent years. Recently anumber of attempts have been taken in this line. Successful Biogasproduction (Ismail and Talib, 2016), eco-composite manufacturing(Sanchez et al., 2014) and carboxymethyl cellulose synthesis (Joshiet al., 2015), from used and recycled cellulosic biomass, are some</p><p>mailto:joshigyaneshfri@gmail.com;</p></li><li><p>G. Joshi et al. / Journal of Cleaner Production 142 (2017) 3759e37683760</p><p>common example for this purpose.Waste paper is difficult to recycle for the production of high</p><p>quality paper because of the reduced fibre quality with short lengthand strength and therefore inevitably goes to landfill (Elliston et al.,2015; Joshi et al., 2015). The maximum ratio (65%) of paper-to-paper recycling results in the production of great quantities of byproducts which finally have to be disposed. With higher cost ofproducing paper from recycled pulp, and disposal of waste fibresunfit for use, finding alternative options to recycle wastepaper is anecessity (Danial et al., 2015). This is the need of hour for cellulosebased industries, excluding pulp and paper, to switch over torecyclable cellulosic waste like waste paper, cotton waste, medicalindustry waste and waste from pulp and paper industry.</p><p>Thus, wastepaper being a cellulose rich biomass provides apotential source for the production of cyanoethyl cellulose (CEC).Cellulose the most common and inexhaustible raw material, pre-sent in waste paper can be converted into various green and usefulspecialty end products and it can be chemically modified to yieldcommercially important cellulose derivatives. Cellulose derivativesare increasingly gaining attention as their application is of higheconomic relevance into diversified industrial end uses in additionto being used as a source for commodity goods (Chauhan et al.,2007; Varshney and Naithani, 2011). Cyanoethylated derivativesof cellulose, cellulosic raw materials like bagasse, bamboo, lantanaandwood and cellulose derivatives have been prepared and studiedconventionally (Bhatt et al., 2007; Hassan et al., 2001; Khullar et al.,2008) but to date none has been commercialized. Among the cya-noethylated materials, considerable attention has been focused onthe investigations of the CEC due to its excellent physical andchemical properties (Chatterjee and Conrad, 1966; Saha et al.,2000). Moreover, increased thermal resistance, microbiologicalresistance, moisture regain and characteristic mechanical proper-ties are thewell documented properties of CEC products. Zhou et al.(2010) demonstrated degree of substitution (DS) as one of the mostsignificant factors which significantly affect the properties of CEC.Degree of substitution (DS) is defined as the average number ofetherified hydroxy groups per anhydrous glucose unit. CEC withhigh DS value could be used as dielectric materials due to its un-usual dielectric properties, namely high dielectric constant andrelatively low dielectric lossfactor. Furthermore, Bhatt et al. (2007)reported that cyanoethylated cellulose can also be used at wet endin paper industries, to improve fold and tear strength of paper.Among waste papers, office waste paper is a major class which canbe used for fibre reutilization. The use of waste paper for the syn-thesis of carboxymethyl and carboxylated cellulose is reported(Joshi et al., 2015;Mahkami and Talaeipour, 2011) but till to date theuse of office wastepaper as a rawmaterial for the production of CEChas not been reported. Moreover, to date no research has describedthe pre-steps for extraction of cellulose from waste paper trulyrequired for the production of CEC of higher grade from real wastepaper in true sense as described in the present study. Consideringthat the office waste paper is renewable, abundant and cheap.Lesser impurity level and low cost extraction of cellulose from of-fice waste paper attracted the attention of this research group forthe production of cyanoethyl cellulose from this mass. The pro-duction of CEC from wastepaper would provide an alternative topaper recycling and it may possibly address this issue of byproductsarising from paper to paper recycling. This also offers an opportu-nity to the effective disposal of the waste and evidently demon-strates a cleaner production approach towards sustainableenvironment management. The principal objective of the presentstudy was to synthesize CEC from office waste paper with highdegree of substitution and to investigate the structure and physicalproperties of the CEC samples. Prompted by aforesaid facts a seriesCEC samples with high DS value were first synthesized successfully</p><p>from office waste paper through a cycle of chemical treatmentscombined with cellulose extraction, alkalization and cyanoethyl-ation. The prepared CEC was characterized by Fourier TransformInfrared (FTIR) spectroscopy, 1H Nuclear Magnetic Resonance(NMR) spectroscopy, Scanning Electron Microscopy (SEM), X-raydiffraction (XRD), solubility and measurements of degree of poly-merization. This work provided a new environmentally friendlymethod to synthesize water-soluble and organic-soluble CEC fromwaste paper. In the view of abundance of wastepaper, and the needto reduce waste generated from paper to paper recycling, the pre-sent study has demonstrated that wastepaper, specifically officewaste paper can serve as a precursor for the production of CECs,while providing an alternative to paper recycling.</p><p>2. Experimental</p><p>2.1. Materials</p><p>Office waste paper (OWP) paper was used as a raw material forthe present study. The samples were collected from the differentoffices of Indian Council of Forestry Research &amp; Education, Dehra-dun, Uttarakhand (India). OWP primarily comprised of photocopierand computer printout papers. The wastepaper was physicallysegregated from non-paper objects such as rubber bands, staples,stickers and others. The sorted waste paper stock was stored inpolyethylene bags at room temperature until needed. All thechemicals used were of analytical grade.</p><p>2.2. Methods</p><p>2.2.1. Characterization of OWPThe OWP stock was processed for pulp production and proxi-</p><p>mate analysis was performed as described in our previous publi-cation (Joshi et al., 2015).</p><p>2.2.2. Extraction of cellulose from OWP for CECs synthesisWaste paper except cellulose contains various objectionable</p><p>chemicals like residual ink, hemicellulose, and lignin which arehighly undesirable from CEC synthesis point of view. Thus prior toCEC synthesis these chemicals were removed to yield a good qualityCEC product with high DS. To achieve it, firstly the OWP wasmanually torn into a size of approximately 2.5 cm2, pulped in ahydrapulper at 12% consistency and subsequently subjected todeinking in a flotation cell at 1% consistency as described in ourprevious publication (Joshi et al., 2015). To leach lignin the pulp wassubsequently treated three times with aqueous NaClO2 (1.25% w/v)at 75 C for an hour according to the procedure demonstrated byOkahisa et al. (2011). Afterwards the delignified pulp was succes-sively treated with aqueous KOH (2%w/v) at 90 C for 2 h to removethe residual ink and hemicelluloses as per the method reported byWang et al. (2013). Cellulose was purified by treatment with anacidified NaClO2 (0.5% w/v) solution at 75 C for 1 h and then withaqueous KOH (5% w/v) at 90 C for 2 h followed by three consec-utive washings with water (75 ml each). This pure cellulosic masswas treated with HCl (1% v/v) at 80 C for 2 h. Finally the sampleswerewashed with deionized water until a neutral pH was recordedthroughout the process. The pure cellulose was then shredded inthe pulp shredder and stored in air tight plastic containers at 4 C.</p><p>2.2.3. Sample preparation prior to CECs synthesisThe cellulose extracted from the OWP was placed in an oven at</p><p>105 2 C for overnight drying. The oven-dried sample was thenpassed through a laboratory mixer in order to avoid the lump for-mation. The disconcerted cellulose was processed for the produc-tion of cyanoethyl cellulose.</p></li><li><p>G. Joshi et al. / Journal of Cleaner Production 142 (2017) 3759e3768 3761</p><p>2.2.4. Cyanoethyl cellulose synthesisA two-step process was used for synthesis of CEC, with the first</p><p>step consisting of alkalization of the cellulose and the second oneconsisting of etherification of the alkali cellulose in a large excess ofacrylonitrile. Different parameters studied for the optimization ofreaction conditions are illustrated in Table 1. In the present studyalkalizationwas conducted under vigorous stirring of cellulose (3 g)with aqueous NaOH [3.24e10.2 M/Anhydro glucose unit (AGU)] forcertain time period (30e70 min) at different temperatures(30e70 C). Here Anhydro glucose unit (AGU) may be defined byusing the example of cellulose. In the formation of cellulose chain,the glucose units are in 6-membered rings, called pyranoses. Allpyranose units in cellulose chain are joined by single oxygen atoms(acetal linkages) between the C-1 of one pyranose ring and the C-4of the next ring. During the formation of acetal linkage a moleculeof water is lost when an alcohol and a hemiacetal react to form anacetal hence the glucose units in the cellulose polymer are referredto as anhydroglucose units.</p><p>After completion of alkalization the excess alkali was squeezedout from the alkaline mixture using laboratory hydraulic press. Thealkali cellulose was then treated with an excess of acrylonitrile(40e90 M/AGU) for a certain time period (50e80 min) at temper-atures varied from 40 to 70 C under constant stirring. During theprocedure the CEC was formed. Excess of acrylonitrile was thenadded to the reaction mixture. A yellow colored solution of cya-noethyl cellulose in excess acrylonitrile is obtained. Excess of alkaliwas neutralized by the addition of 5 M CH3COOH in cold conditionsand the polymer was subsequently precipitated from the reactionmixture in the form of porous white flakes by an excess and slowaddition of an ethanol-water mixture (1:1 by volume). The reactionproduct was filtered off and washed first with hot water and thenwith cold water followed by drying in vacuum at 60 C.</p><p>2.2.5. Yield measurement for synthesized CECsThe yield of all CEC products was calculated on the basis of</p><p>theoretical yield and actual yield by using the following formula:</p><p>Yield % A=B 100</p><p>where A...</p></li></ul>


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