Huchuan Wang, Yuming Zhou, Qingzhao Yao, Yunyun Bu, Yiyi Chen, Wei Sun
March 21, 2015
The precipitation of CaCO 3 (calcite, vaterite, aragonite and calcium carbonate hydrates) and CaSO 4 (calcium sulfate anhydride, calcium sulfate dihydrate and calcium sulfate hemihydrates) scale on pipe surfaces widely occurs in numerous industrial processes. For the control of CaCO 3 and CaSO 4 scales, a novel environmentally friendly scale inhibitor, maleic anhydride (MA)-allypolyethoxy carboxylate (APEM9), was synthesized. MA-APEM9 was characterized by Fourier transform infra-red spectroscopy (FT-IR) and 1 H-NMR. The inhibitor property of the MA-APEM9 copolymer towards CaCO 3 and CaSO 4 in the artificial cooling water was studied by static scale inhibition tests. The effect on formation of CaCO 3 and CaSO 4 was investigated with a combination of scanning electronic microscopy (SEM) and transmission electron microscopy (TEM) analysis. The observation showed that MA-APEM9 was a much better inhibitor both for CaCO 3 and CaSO 4 compared to the commercial inhibitors. An inhibition mechanism is proposed. It shows that the interactions between calcium and allyl-terminated PMA are the fundamental impetus to restrain the formation of the scale in cooling water systems. The MA-APEM9 Inhibitor can be used safely in cooling water systems.