Ceric-induced grafting of methyl acrylate onto sodium salt of partially carboxymethylated sodium alginate

Grafting of methyl acrylate (MA) onto the sodium salt of partially carboxymethylated sodium alginate (Na-PCMSA, <(DS)over bar> = 1.625) has been carried out using eerie ammonium nitrate (CAN) as a redox initiator in an aqueous medium. The optimized reaction conditions affording maximum percentage of grafting are determined by varying the concentrations of nitric acid, CAN, Na-PCMSA and MA, and also temperature and time. The effects of these parameters on the grafting yields and the rates of polymerization, graft copolymerization and homopolymerization have also been studied and the results are discussed. The overall activation energy for grafting has been found to be 32.4 kJ/mol. The overall thermal stability of Na-PCMSA has been found to decrease as a result of the grafting. (C) 1998 Elsevier Science Ltd. All rights reserved.