Synthesis and characterization of hypochlorite oxidized poly (methacrylic acid) starch composites

Maize starches were independently polymerized with methacrylic acid (MAA) to different levels and their behaviour towards hypochlorite oxidation was examined and compared with native and initiator-treated starches. Synthesis of poly (MAA) starch composites was performed using a potassium permanganate/citric acid initiation system. Hypochlorite treatment was carried out using sodium hypochlorite at a concentration of 3 and 10 g/l active chlorine, for 15-60 min at 50 degrees C and pH 9. The oxidation reaction was studied with respect to chlorine consumption and carboxyl content as well as apparent viscosity at various rates of shear. Application of these composites before and after hypochlorite treatment to cotton fabric was also carried out to evaluate their suitability as sizing agents. The results are discussed with respect to the structure of the original starch and the poly (MAA)-starch composite. (C) 1996 Elsevier Science Limited