Evaluation of maleic acid‐based copolymers containing polyoxyethylene ether as inhibitors for CaCO 3 scale

Polymer scale inhibitors have been widely used to reduce the loss caused by mineral scaling in circulating cooling water systems. In this article, four maleic acid‐based copolymers [hydrolyzed polymaleic anhydride (HPMA)‐AEO] containing different fatty alcohol polyoxyethylene ether (such as AEO‐9, AEO‐10, AEO‐15, and AEO‐20) are prepared by the way of free‐radical copolymerization and characterized using Fourier transform infrared (FTIR), 1 H NMR, and gel permeation chromatographic (GPC) techniques. The effects of HPMA‐AEO on CaCO 3 scale are studied in several aspects (such as dose, Ca 2+ concentration, temperature, inhibition time, pH, the ratio of EO:carboxyl, and the relative supersaturation of CaCO 3 solution) by static experiments. The CaCO 3 scaling process with dosing of HPMA‐AEO‐9 is investigated under dynamic tests. CaCO 3 deposits and precipitate in the presence of HPMA‐AEO‐9 are analyzed using scanning electronic microscope (SEM) and X‐ray diffraction (XRD). The results show that the performance of HPMA‐AEO against CaCO 3 scale highly depends upon the ratio of EO:carboxyl; the introduction of AEO group can significantly improve the performance of HPMA‐AEO to tolerate high alkalinity, high hardness, and high temperature; the presence of HPMA‐AEO‐9 can obviously affect the CaCO 3 scaling process on the tube wall through interfering with nucleation process and crystal growth process and significantly alter the surface morphology and crystal form of CaCO 3 deposits. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47470