Graft Copolymerization of Methyl Acrylate onto Sodium Alginate Initiated by Potassium Diperiodatocup

Anovel redox system, potassium diperiodatocuprate(III) (DPC) sodium alginate (SA), was employed to initiate the graft copolymerization of methyl acrylate (MA) onto SA in alkali medium. The effects of reaction variables, such as the initiator concentration, the ratio of monomer to SA, the SA backbone concentration, as well as temperature and time, were investigated, and the grafting conditions were optimized. Graft copolymers with both high grafting efficiency and high percentage of grafting were obtained, indicating that DPC SA redox system is an efficient initiator for this graft copolymerization. The structures and the thermal stability of SA and SA-g-PMA were characterized by scanning electron microscope, infrared spectroscopy and thermogravimetric analysis. A mechanism is proposed to explain the generation of radicals and the initiation.