Abstract: Cationic modified starch was synthesized with starch and diallyldimethylammonium chloride as raw material by using ammonium persulfate/carbamide initiation system.The factors on the graft copolymerization were discussed,and the flocculating properties of resultant were investigated using diatomite-containing suspension.Experimented results show that the graft polymer has good water-solubility,higher grafting level,higher cationic degree and excellent flocculation performances.The structure of the copolymer ...