Synthesis Of Polymer MA-APEA And Study On The Effect Of Deprotonation Degree On Calcium Scale

Polycarboxylic acid scale inhibitors,such as homopolymers or copolymers of maleic acid and acrylic acid,are favored for their good calcium scale inhibition properties,as well as non-phosphorus,nitrogen-free,and environmental friendliness.In this study,maleic anhydride and allyloxy polyoxyethylene ether carboxylic acid were used as raw materials,and ammonium persulfate was used as the initiator.The polymer scale inhibitor MA-APEA was synthesized by free radical polymerization.The study is mainly focused on the investigation of the effect of MA-APEA deprotonation on the inhibition of calcium scale by static scale inhibition method;at the same time,the effects of the conditions such as addition amount,temperature,Ca2+concentration and pH on the inhibition of calcium carbonate scale of the polymer were also studied respectively;the weight loss method was used to study the effect of MA-APEA on the corrosion inhibition performance of A3 carbon steel and the degree of deprotonation on the corrosion inhibition performance;the morphology and crystal form distribution of calcium carbonate crystals were analyzed by scanning electron microscope and X-ray diffraction,furthermore,the scale inhibition mechanism of MA-APEA was explored.The results show that different degrees of deprotonation of the polymer have different influences on different calcium scale and corrosion inhibition of low carbon steel.The performance of the polymer to withstand high alkalinity and high hardness and high temperature decreases with increase in the degree of deprotonation.The change in the degree of deprotonation influences the conversion of aragonite and vaterite to calcite,and hardly impacts the crystal morphology of CaCO₃ crystals.MA-APEA has proven to be an excellent calcium scale inhibitor.