Evaluation of maleic acid‐based copolymers containing polyoxyethylene ether as inhibitors for CaCO₃ scale

Abstract

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), 1H NMR, and gel permeation chromatographic (GPC) techniques. The effects of HPMA‐AEO on CaCO3 scale are studied in several aspects (such as dose, Ca2+ concentration, temperature, inhibition time, pH, the ratio of EO:carboxyl, and the relative supersaturation of CaCO3 solution) by static experiments. The CaCO3 scaling process with dosing of HPMA‐AEO‐9 is investigated under dynamic tests. CaCO3 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 CaCO3 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 CaCO3 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 CaCO3 deposits. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47470

Stable Binding Conformations of Polymaleic and Polyacrylic Acids at a Calcite Surface in the Presence of Countercations: A Metadynamics Study

“…Consequently, it can be speculated that the binding conformations of ionic polymer additives at the calcite surface are strongly affected by dissolved ions, even in real systems. This speculation appears to be qualitatively consistent with an experimental study by Wang et al in which maleic acid-based copolymers containing polyoxyethylene ether efficiently inhibited CaCO 3 scale growth at low Ca 2+ concentrations . Strictly, the repulsive interaction between carboxyl moieties within the additive would also affect the binding conformation .…”

Formation and Inhibition of Calcium Carbonate Crystals under Cathodic Polarization Conditions

“…The value of η s changed little when the PBTCA concentration continued to increase. Many scale inhibitors, including PBTCA can adsorb and chelate with calcium ions, reducing the supersaturation of the scaling solution and thus reducing the nucleation rate of CaCO 3 crystals, therefore inhibiting the deposition of CaCO 3 [23,24]. During the nucleation of the crystal, the scale inhibitor might also form slightly soluble calcium salts with calcium ions and encapsulate the surface of solid impurities which act as a crystal center, thereby preventing the nucleation and growth of CaCO 3 crystals on the solid impurities [25].…”

Synthesis, characterization and properties of a novel environmentally friendly ternary hydrophilic copolymer

“…12 Common functional groups are carboxylic acid groups, sulfonic acid groups, and hydroxyl groups. 13 Based on the complex water environment in the oilfield, multifunctional polymeric scale inhibitors are usually used. The hydrophilic carboxyl group is the main functional group to inhibit calcium carbonate, but its low dispersion hinders the efficiency of scale inhibition.…”