Abstract: With sodium persulfate as the initiator and sodium hydrosulfite as the reducer , maleic anhydride and acrylic acid were copolymerized in an aqueous solution to synthesize the tittle copolymer , which can be used as STPP substitute in laundry powder. The weight ratio of maleic anhydride to acrylic acid was 1:2. The weight percentages of the initiator and the reducer to the monomers were respectively 4.0％ and 1.9％. The polymerization was carried out 90 oC for 1h. The production was a transparent liquid with a low viscosity and at light colour. It has good dispersivity and the chelating power was 518 mg CaCO3/g.

Key words: maleic anhydride-acrylic acid copolymer, aqueous solution polymerization, initiator, reducer, STPP substitute in laundry powder