缓凝型聚羧酸系高性能减水剂合成研究

Research on synthesis of a set-retarding type polycarboxylate superplasticizer

夏季混凝土施工和大体积混凝土需要较长的凝结时间。研究了以不同分子质量的大单体烯丙基聚氧乙烯醚(APEG)、丙烯酸(AA)、顺丁烯二酸(MA)和缓凝型单体(GA)合成缓凝型聚羧酸系减水剂,确定了合成产品的最佳工艺条件为:n(APEG1200)∶n(AA)∶n(MA)∶n(GA)=1.0∶0.5∶2.0∶0.5;采用引发剂过硫酸铵[(NH4)2S2O8]用量为单体总质量的2.0%。与市场上的同类产品相比,合成的缓凝型聚羧酸系减水剂具有明显的缓凝作用。

The construction of the concrete in summer and the mass concrete need a long setting time. A set retarding-type polycarboxylate superplasticizer was synthesized by different molecular macro-monomer APEG, AA, MA and a set retarding-type monomer（GA）. The experiment results showed that the copolymer had a significant set retarding property when the molar ratio of APEG, AA, MA and GA was 1.0：0.5：2.0：0.5. The initiator agent used was （NH4）2S2O8, which amount was 2.0% of the total monomers. Compared with the like product in the market, the copolymer had an excellent property.