Microwave assisted synthesis and characterization of sodium alginate-graft-poly(N,N′-dimethylacrylamide)

Modification of sodium alginate (NaAlg) was carried out using N,N′-dimethylacrylamide (DMAAm) as a monomer and azobisizobutyronitrile (AIBN) as an initiator under microwave irradiation. The effect of reaction conditions such as concentrations of DMAAm, AIBN, NaAlg as well as microwave power and temperature on grafting and grafting efficiency has been explored. Maximum grafting and grafting efficiency has been observed at 1 h of grafting time, 0.291 M of DMAAm concentration, 500 W microwave irradiation power, 0.134 M of AIBN concentration, 75 °C of reaction temperature and 0.5 g/dL of NaAlg concentration. The grafted copolymer has been characterized by FTIR, DSC, TGA, 13C NMR, XRD, SEM, and GPC analysis. Cytotoxicity as standard MTT assay, apoptotic and necrotic effects of graft copolymer were investigated on L929 fibroblast cell. It has been found that the grafted copolymer is biocompatible and thermally more stable than the ungrafted alginate.