Modification of alginate through the grafting of 2-acrylamidoglycolic acid and study of physicochemical properties in terms of swelling capacity, metal ion sorption, flocculation and biodegradability

The present paper reports the modification of alginate through the grafting of 2-acrylamidoglycolic acid by free radical polymerization using an efficient potassium peroxydiphosphate/silver nitrate redox system in an inert atmosphere. The reaction conditions for maximum grafting have been optimized by varying the reaction variables including the concentration of 2-acrylamidoglycolic acid (2.0 x 10(-2)-7.3 x 10(-2) mol dm(-3)), potassium peroxydiphosphate (0.4 x 10(-2)-2.0 x 10(-2) mol dm(-3)), silver nitrate (1.2 x 10(-3)-4.4 x 10(-3) mol dm(-3)), sulphuric acid (1.0 x 10(-3)-8 x 10(-3) mol dm(-3)), alginate (0.4-1.8 g dm(-3)) along with time duration (60-180 min) and temperature (30-50 degrees C). Water swelling capacity, metal ion sorption, flocculation and resistance to biodegradability studies of synthesized graft copolymer have been performed with respect to the parent polymer. The graft copolymer has been characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. (C) 2010 Elsevier Ltd. All rights reserved.