SYNTHESIS AND CHARACTERIZATION OF POLY(BUTYL METHACRYLATE) GRAFTED SODIUM SALT OF PARTIALLY CARBOXYMETHYLATED GUAR GUM

摘要

An unreported graft copolymer of polybutyl methacrylate (PBMA) with sodium salt of partially carboxymethylatcd guar gum (Na-PCMGG, DS = 0.497) was synthesized using ceric ammonium nitrate (CAN) as a redox initiator. The reaction variables including concentrations of initiator, nitric acid, monomer and amount of the backbone, as well as time and temperature, were varied to establish the optimal reaction conditions. The influence of these reaction variables on the grafting yields was discussed. The kinetic scheme of free radical graft copolymerization was also .proposed and the experimental results were found to agree very well with it. The reactivity of butyl methacrylate towards graft copolymerization has been compared with that reported in literature and a plausible explanation has been furnished. The graft copolymer sample was characterized by the FT-IR, SEM and TGA techniques. The synthesized graft copolymer, Na-PCMGG-g-PBMA, may find application as a tablet matrix for the release of a model drug.