Synthesis and properties of a water soluble graft (chitosan-g-2-acrylamidoglycolic acid) copolymer

The present paper reports the graft copolymerization of 2-acrylamidoglycolic acid onto chitosan by using potassium bromate/silver nitrate as an efficient redox initiator in an inert atmosphere. The effect of reaction conditions on grafting parameters i.e. grafting ratio, efficiency, conversion, add on, homopolymer and rate of grafting has been studied. Experimental results show that maximum grafting has been obtained at 0.4 g dm(-3) concentration of chitosan, 8.0 x 10(-2) mol dm(-3) concentration of 2-acrylamidoglycolic acid and 1.0 x 10(-3) mol dm(-3) concentration of hydrogen ion. It has also been observed that grafting ratio, add on, conversion, efficiency and rate of grafting increase up to 3.2 x 10(-3) mol dm(-3) of silver nitrate and 1.7 x 10(-2) mol dm(-3) of potassium bromate. Time (120 min) and temperature (40 degrees C) were kept constant during reaction. The physicochemical properties of graft copolymer synthesized have been performed in terms of water swelling, metal ion sorption, flocculation and resistance to biodegradability with respect to the chitosan as a parent polymer. The graft copolymer has been characterized by Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis. (C) 2012 Elsevier B.V. All rights reserved.