磷酸酯基团改性聚羧酸减水剂的合成与抗高岭土性能研究

Preparation and anti-kaolin performance of polycarboxylate superplasticizer modified by phosphate ester group

以乙醇胺与磷酸进行酯化反应制得乙醇胺磷酸酯,再与马来酸酐进行开环反应制得磷酸酯改性单体MA-POE,并进一步与丙烯酸(AA)及异戊烯基聚氧乙烯醚(TPEG)进行水溶液自由基共聚合成磷酸酯基团改性聚羧酸减水剂。考察了AA、磷酸酯单体及TPEG三者比例、引发剂用量、催化剂用量等对减水剂分散性的影响,并与市售普通聚羧酸减水剂的抗高岭土性能进行了对比。结果表明,当n(AA)∶n(磷酸单体)∶n(TPEG)=4∶1∶1,双氧水用量为单体总物质的量的4%,n(抗坏血酸)∶n(双氧水)=0.50时,合成的减水剂分散及分散保持性能较优,对高岭土的敏感性优于市售减水剂,这主要源于其对高岭土的吸附作用更小。

Phosphate ester modified monomer MA-POE was synthesized by ring opening reaction of maleic anhydride and ethanolamine phosphate prepared through esterification reaction of ethanolamine and phosphoric acid. Furthermore,free radical copolymerization of acrylic acid （AA）, MA-POE and isopentenepolyoxyethylcne ether （TPEG） in aqueous solution was carried out to synthesize water reducing agent modified by phosphate group. Effects of molar ratio of acrylic acid,MA-POE,initiator dosage and catalysis agent dosage on the dispersibility and dispersion retention of superplasticizer were systematically studied. When acrylic acid：MA-POE ：isopentenepolyoxyethylene ether （molar ratio） =4：1：1, hydrogen peroxide dosage 4%, ascorbic acid：hydrogen peroxide = 0.50,the obtained superplasticizer show the best dispersibility and dispersion retention performance,a better endurance of kaolin than that of two kinds of water reducing agent on sale,which is mainly due to its less adsorption to kaolin.