Graft copolymerization of methacrylic acid onto carboxymethyl chitosan

Carboxymethyl chitosan (CMCTS) was prepared and characterized by FTIR, ¹H NMR, and elemental analysis. The graft copolymerization of methacrylic acid (MAA) onto CMCTS using ammonium persulfate (APS) as an initiator was carried out in an aqueous solution. Evidence of grafting was obtained by comparison of FTIR spectra of CMCTS and the grafted copolymer as well as solubility characteristics of the products. The effects of APS, MAA, reaction temperature and time on graft copolymerization were studied by determining the grafting parameters such as grafting percentage and grafting efficiency. With keeping other conditions constant, the optimum conditions were shown as following: APS]=8 mmol/l, MAA]=2.4 mol/l, reaction temperature=60-70 °C, reaction time=120 min.