Carbohydrate Polymers 97 (2013) 18–25 Contents lists available at SciVerse ScienceDirect Carbohydrate Polymers jo u r n al homep age: www.elsevier.com/locate/carbpol Graft copolymers from cellulose: Synthesis, characterization and evaluation Vijay Kumar Thakur a,∗ , Manju Kumari Thakur b , Raju Kumar Gupta c,∗∗ a Department of Materials Science and Engineering, Iowa State University of Science and Technology, Ames, IA 50011, USA b Division of Chemistry, Govt. Degree College Sarkaghat, Himachal Pradesh University Shimla, 171005, India c Department of Chemical Engineering, Indian Institute of Technology Kanpur, 208016, India a r t i c l e i n f o Article history: Received 25 March 2013 Received in revised form 14 April 2013 Accepted 17 April 2013 Available online 30 April 2013 Keywords: Cellulose Graft copolymers Characterization Chemical resistance Moisture absorbance Thermal and morphological behavior a b s t r a c t Cellulose, a linear polysaccharide polymer with numerous glucose monosaccharide units is of enormous interest because of its applications in biosorption, biomedical, packaging, biofiltration and biocomposites. In this study, cellulose-graft-poly(butyl acrylate) copolymers were synthesized under microwave con- ditions. Effects of microwave radiation doses and different reaction parameters were optimized to get the optimum percentage of grafting. The dependence of optimum conditions for better physico-chemical properties of the cellulosic polymers was also determined. Fourier transform infrared spectroscopy (FT- IR) analysis was used to authenticate the chemical reaction taking place between cellulosic polymers and monomer. The thermogravimetric behavior of the raw and grafted cellulosic polymers was characterized by thermogravimetric analysis (TGA). The surface structure of the raw and grafted cellulosic polymers was analyzed through scanning electron microscopy (SEM). The graft copolymers have been found to be more moisture resistant and also showed better chemical and thermal resistance. Published by Elsevier Ltd. 1. Introduction The economy of depleting petroleum resources coupled with increasing environmental have ignited the interest in the use of renewable cellulosic polymers from different resources for mak- ing new materials (Nazi, Malek, & Kotek, 2012; Qiu, Ren, & Hu, 2012). Natural cellulosic polymers such as lignocellulosic natural fibers offer well-known advantages as compared to the traditional synthetic materials which include eco-friendliness, toxicologically harmless, biodegradability, carbon dioxide (CO 2 ) neutral, easy availability, enhanced energy recovery, non corrosive nature and usually lower cost (Singha & Thakur, 2010a). These cellulosic natu- ral polymers are also characterized by a huge degree of variability and diversity in their properties depending upon the place of their origin (Thakur & Singha, 2011a). During the last few years a great deal of interest has been dedicated to the natural cellulosic poly- mers based materials as the unique properties exhibited by natural polymers are never offered by non cellulosic polymers. Naturally derived cellulosic polymers are usually eco-friendly, and therefore materials prepared using these polymers such as composites rein- forced with natural fibers should also be eco-friendly (Liu, Wu, & ∗ Corresponding author. Tel.: +1 515 294 1214; fax: +1 515 294 5444. ∗∗ Corresponding author. E-mail addresses: vijayisu@hotmail.com (V.K. Thakur), guptark@iitk.ac.in (R.K. Gupta). Zhang, 2009; Singha & Thakur, 2010a). Polymer composite mate- rials containing cellulosic polymers exhibit enhanced properties and are less expensive than the starting polymer in overall mate- rial costs (Singha & Thakur, 2010b; Thakur & Singha, 2011b). Novel green materials based upon natural cellulosic polymers have been the subject of intense international research since last two decades and a number of practical applications are now emerging in various fields, including packaging, biomedical, bioenergy, bioplastics, and in aerospace industry(Akar, Altinisik, & Seki, 2012; Alila, Ferraria, do Rego, & Boufi, 2009; Bao, Ma, & Sun, 2012). Commercial inter- est in manufacturing different products using cellulosic polymers is driven by the derivation of these polymers from environmental friendly renewable sources as well as by their specific properties including biodegradability (Cheema, El-Shafei, & Hauser, 2013; Wu, 2012). However the natural cellulosic polymers are inferior to harsh environmental conditions due to hydrophilic natural of the cel- lulose and need to be modified for superior applications (Thakur, Singha, & Thakur, 2012a). Among various natural cellulosic polymers, only few studies have been reported on the cellulosic pine needles based materials (Singha & Thakur, 2009; Thakur & Singha, 2011a). These needles are obtained from Pinus which is one of the most popular trees in almost all around the globe and is a rich source of cellulose in the form of pine needles. These needles are automatically shed off by the trees during whole year especially in summer and are one of the major reasons for destruction of different kinds of flora and fauna. In order to increase the physico-chemical properties of 0144-8617/$ – see front matter. Published by Elsevier Ltd. http://dx.doi.org/10.1016/j.carbpol.2013.04.069