抗泥缓释型聚羧酸减水剂的制备及性能研究

Study on preparation and properties of anti-clay slow-released polycarboxylate superplasticizer

以丙烯酸(AA)、丙烯酸羟乙酯(HEA)、2-羟乙基甲基丙烯酸酯磷酸酯(HEMAP)、异戊烯醇聚氧乙烯醚(TPEG)为反应单体,以过氧化氢(H_(2)O_(2))/抗坏血酸(Vc)为引发剂,巯基丙酸为链转移剂,通过自由基聚合制得抗泥缓释型聚羧酸减水剂(PCP)。通过红外光谱(FTIR)表征了减水剂的分子结构、采用热重(TG)分析了减水剂的热学性能。通过单因素试验分别研究了反应温度、功能单体掺量对PCP分散性的影响。结果表明,当HEMAP用量为TPEG质量的2%,n(TPEG)∶n(AA)∶n(HEA)=1∶2∶2,反应温度为65℃时,PCP的分散性最佳。与普通聚羧酸减水剂相比,PCP对蒙脱土的敏感性低,且具有一定的缓释功能。

A novel anti-clay type polycarboxylate superplasticizer was synthesized through radical polymerization by using acrylic acid(AA),hydroethyl methacrylate(HEA),2-hydroxyethyl methacrylate phosphate(HEMAP)as reactive monomers,hydrogen peroxide(H_(2)O_(2))and ascorbic acid(Vc)as initiators,and thioglycolic acid as the chain transfer agent.The molecular structure of the superplasticizer was characterized by infrared spectroscopy(FTIR),and the thermal properties of the superplasticizer was analyzed by thermogravimetry(TG).The effects of reaction temperature and the amount of functional monomer on PCP performance were studied by single factor test.The results showed that PCP had the best performance when HEMAP was added at 2%of TPEG mass,n(TPEG)∶n(AA)∶n(HEA)=1∶2∶2 and the reaction temperature was 65℃.Compared with common polycarboxylate water reducer,the synthesized superplasticizer PCP is less sensitive to montmorillonite and has a certain slow-release function.