Synthesis of MA-SAS-HEMA terpolymers and their scale inhibition properties

Abstract

In order to solve the problem of water pollution caused by traditional phosphorus-containing scale inhibitors, a phosphorus-free MA-SAS-HEMA copolymer scale inhibitor was prepared by aqueous solution free radical polymerization using maleic anhydride (MA), sodium allylsulfonate (SAS) and hydroxyethyl methacrylate (HEMA) as synthetic monomers. The microstructure of the copolymer and the thermal stability were characterized by infrared spectroscopy, gel permeation chromatography and thermogravimetric analysis. The scale inhibition performance of the copolymer was explored by static scale inhibition method. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the calcium carbonate and calcium sulfate crystals produced before and after the addition of MA-SAS-HEMA copolymer to explore the scale inhibition mechanism of the copolymer. The results of static scale inhibition show that the copolymer can achieve good scale inhibition effect at low concentration, and are highly temperature resistant. The scale inhibition performance is stable in high alkalinity and high hardness water. The results of XRD and SEM showed that the scale structure was obviously loose and the scale inhibition effect was good after adding the copolymer. The crystal form of calcium carbonate changed, the characteristic peak of calcite decreased significantly, and the characteristic peaks of metastable vaterite and aragonite appeared. The crystal form of calcium sulfate did not change but the crystallinity was greatly reduced. The carboxylic acid group in the MA-SAS-HEMA copolymer.

Keywords

• maleic anhydride
• copolymer scale inhibitor
• static scale inhibition
• calcium carbonate
• scale inhibition mechanism