Influence of Heat Treatment on the Performance of Polymers as Gypsum (CaSO4 · 2H2O) Scale Inhibitors for Industrial Water Applications

Abstract

Abstract The inhibition of gypsum precipitation by homo-, co-, and terpolymers has been examined in aqueous solution. It has been found that polymer performance as gypsum inhibitor depends upon polymer composition, type of comonomer, and functional groups. Results on the evaluation of polymers suggest that compared to co- and terpolymers, homopolymers containing carboxyl group are effective gypsum inhibitors. The impact of heat treatment (150°C to 240°C) on the performance of various homo-, co-, and teropolymers as gypsum inhibitors has also been investigated. It has been observed that all polymers lose performance to a varying degree when exposed to thermal treatment. Performance data on co- and terpolymers containing amido group show improved performance after heat treatment suggesting the formation of carboxyl group. Scanning electron microscopic investigations of gypsum crystals grown in the presence of polymers show that structures of these crystals are highly modified.