Graft Copolymerization of Sodium Acrylate onto Chitosan via Redox Polymerization

The graft copolymerization of sodium acrylate onto chitosan in alkali medium was investigated, using redox system, potassium diperiodacuprate(III) (DPC) chitosan. The graft copolymer was characterized by Fourier transform infrared spectra analysis, X-ray diffraction analysis, differential scanning calorimetric, thermogravimetric analysis, and scanning electron microscopy techniques. A tentative mechanism is proposed to explain the generation of radicals and the initiation. The effects of reaction variables, such as the initiator concentration, the ratio of monomer to chitosan, and pH, as well as, reaction temperature and time were investigated, and the grafting conditions were optimized. Graft copolymer with high grafting efficiency was obtained, which indicated that DPC chitosan redox system is an efficient initiator for this graft copolymerization. The graft copolymer was used as the compatibilizer in blends of poly(methyl methacrylate) (PMMA) and chitosan. The scanning electron microscope micrographs indicated that the graft copolymer improved the compatibility of the blend. At the same time, the blend is expected to improve the biodegradability of the PMMA.