Graft copolymerization of itaconic acid onto sodium alginate using benzoyl peroxide

Graft copolymers of sodium alginate (NaAlg) with itaconic acid (IA) were prepared in aqueous solution using benzoyl peroxide (BPO) as the initiator. Grafted copolymers (NaAlg-g-PIA) were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, scanning electron microscopy and thermogravimetric analysis. The grafting parameters, including the graft yield (GY%) of the graft copolymer and the grafting efficiency (GE%) of the reaction were evaluated comparatively. The effects of the reaction variables such as the reaction time, temperature, percentage of sodium alginate, monomer and initiator concentrations on these parameters were studied. It was observed that GY and GE first increased and then decreased with increasing polymerization temperature, concentrations of IA, and BPO. The optimum grafting conditions for maximum graft yield were obtained with reaction time of 1 h, reaction temperature of 85 °C, IA concentration of 1.38 M, BPO concentration of 1.82 × 10−2 M and percentage of NaAlg 1.5 g/dL.