Synthesis and application of cationic starch graft polymer by using the complex initiation system

A graft copolymer was synthesized by graft copolymerization of starch with acrylamide (AM) and acrylacyloxyethyltrimethyl ammonium chloride (AAC). The copolymerization was carried out by using a complex initiation system of urea [CO(NH2)2] and ammonium persulfate [(NH4)2S2O8]. The effect of reaction conditions on graft copolymerization and the application of the polymer as the flocculant were investigated. Experiments showed that a graft copolymer with higher grafting level and higher intrinsic viscosity could be obtained by changing the method of monomer addition and by controlling the ratio of AAC to AM. The application test showed that the results of treatment of two kinds of industrial waste water by the grafted starch [S-g-P(AM-co-AAC)] were better than those treated with cationic polyacrylamide (CPAM).