Abstract: A new type of polyether copolymer—allyloxy polyether carboxylic acid sodium/acrylic acid(APEX/AA) was synthesized using water as solvent and APEX and AA as monomers. Polymer APEX/AA was characterized by infrared spectroscopy, thermogravimetric analysis and gel permeation chromatography. The dosage of APEX/AA, calcium ion concentration in solution, pH and temperature were evaluated on phosphate calcium scale inhibition efficiency through static method. The results show that the polymer APEX/AA has good thermal stability at temperature above 350 ℃, and its relative molecular mass distribution is controllable(PDI=1.41～1.88). The phosphate calcium scale inhibition efficiency of APEX/AA reached 100% when a concentration of 6 mg/L aqueous system was used. The results show that APEX/AA is suitable for water with a high calcium ion concentration（200~2000 mg/L）, high pH（7.5~11.0） and high temperature(75~95 ℃). The scale inhibition effect of APEX/AA is superior to that of commercial calcium phosphate scale inhibitors such as 1-hydroxyethylidine-1,1-diphosphonic acid(HEDP), hydroxypropyl acrylate/acrylic acid(T-225) and 2-phosphonobutane-1,2,4-tricarboxylic acid(PBTCA), indicating that APEX/AA is an excellent non-phosphorus phosphate calcium scale inhibitor in the industrial circulating water systems.

Key words: circulating cooling water, non-phosphorus copolymer, calcium phosphate