Synthesis and characterization of carboxymethyl cellulose from office waste paper: A greener approach towards waste management Gyanesh Joshi a,⇑ , Sanjay Naithani b , V.K. Varshney c , Surendra S. Bisht b , Vikas Rana a , P.K. Gupta a a Cellulose and Paper Division, Forest Research Institute, Dehradun 248006, India b Chemistry of Forest Products Division, Institute of Wood Science & Technology, Bangalore 560003, India c Chemistry Division, Forest Research Institute, Dehradun 248006, India article info Article history: Received 15 July 2014 Accepted 21 November 2014 Available online 24 December 2014 Keywords: Waste-paper Carboxymethyl cellulose Degree of substitution Pulping Deinking abstract In the present study, functionalization of mixed office waste (MOW) paper has been carried out to syn- thesize carboxymethyl cellulose, a most widely used product for various applications. MOW was pulped and deinked prior to carboxymethylation. The deinked pulp yield was 80.62 ± 2.0% with 72.30 ± 1.50% deinkability factor. The deinked pulp was converted to CMC by alkalization followed by etherification using NaOH and ClCH 2 COONa respectively, in an alcoholic medium. Maximum degree of substitution (DS) (1.07) of prepared CMC was achieved at 50 °C with 0.094 M and 0.108 M concentrations of NaOH and ClCH 2 COONa respectively for 3 h reaction time. The rheological characteristics of 1–3% aqueous solu- tion of optimized CMC product showed the non-Newtonian pseudoplastic behavior. Fourier transform infra red (FTIR), nuclear magnetic resonance (NMR) and scanning electron microscope (SEM) study were used to characterize the CMC product. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction The conversion of waste materials into useful products would alleviate a variety of socioeconomic problems such as providing a greener approach to manufacturing. Recycling of waste has huge environmental and economical benefits as recycling of one ton of waste paper saves 17 trees and 7000 gallons of water (ITC, 2014). Across the world, lots of waste is raised on a daily base and yet the economic systems of these states continue to dwindle una- bated. These wastes could be recycled into the products of societal and economic interests. Paper is a significant component of our daily life and likewise one of the most prominent cellulosic bio- mass wastes produced in an ample amount in several subjects (Gulsoy et al., 2013). The number of times paper can be repro- cessed by paper industry is limited due to the shortening of the fiber length and the resulting reduction in tensile strength. Thus, the loss of paper making properties causes it to occupy 30–40% of landfill sites in developed countries (Adhikari et al., 2008). In accession to this, the cellulosic rich fibers, left over from the pro- cess of papermaking, are discharged with the wastewater in amounts of several thousand tons a year (Nikolov et al., 2000). Fee- ble mechanical strength of waste paper has some drawbacks to use in the paper industry alone. However, derivatives of waste paper can find applications in other industrial areas. Thus, chemical adjustment of its cellulosic fibers in the yield of different cellulose derivatives is an additional possible way for its employment and management (Ünlü, 2013). Cellulose is the most abundant polymer on earth, which fixes it also the most common organic compound. Fair yield of cellulose via photosynthesis is estimated around 830 million metric tons per annum. As 40% of dry-weight of crops is composed of cellulose and its annual output is approximately 200 million tons (Ünlü, 2013). Plants contain approximately 33% cellulose whereas wood contains around 50% and cotton contains 90%. Cellulose is a linear and fairly rigid homopolymer consisting of D-anhydroglucopyra- nose units (AGU). These units are linked together by b-(1–4) glyco- sidic bonds formed between C-1 and C-4 of adjacent glucose moieties (Klemm et al., 2001). Most of the cellulose is extensively used as a raw material by the paper industry for the production of paper and cardboard products (Bachheti et al., 2010; Dutt et al., 2011) and a small fraction is used in the production of commodity materials and value added carboxymethyl cellulose and methyl cellulose, etc. Moreover, it can be chemically altered to pay value added cellulose derivatives such as carboxymethyl cellulose, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, cyano- ethyl cellulose, and so forth (Varsney and Naithani, 2011). Among all these modified cellulosic products, CMC is manufactured in sig- nificant amounts due to its wide commercial applications with http://dx.doi.org/10.1016/j.wasman.2014.11.015 0956-053X/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding authors. Tel.: +91 1352224387; fax: +91 1352756865. E-mail addresses: joshig@icfre.org, gyaneshjoshi14@gmail.com (G. Joshi). Waste Management 38 (2015) 33–40 Contents lists available at ScienceDirect Waste Management journal homepage: www.elsevier.com/locate/wasman