梳形聚羧酸系高效减水剂的研究

Study of Comb-like Polycarboxylate Type Superplasticizer

应用高分子设计原理,合成了一种低坍损梳形聚羧酸系高效减水剂。考察了引发剂用量、单体摩尔比及反应时间对其分散性能的影响。结果表明,在甲基丙烯酸/甲基烯丙基磺酸钠/聚氧化乙烯丙烯酸酯摩尔比56:12:32,引发剂过硫酸铵用量占单体总量2.5%,反应温度80℃,反应时间6 h 条件下,合成的聚羧酸系减水剂水泥净浆流动度可达238mm。用此减水剂配制的混凝土,在减水剂用量0.2%时,减水率达22.5%,混凝土的坍落度60 min 内几乎无损失。

Based on molecular design theory of polymer,a kind of low slump loss comb - like polycarboxylate type superplasticizer was synthesized. The effects of initiator amount, the molar ratio of moners and reaction time on its dispersivity were examined. The result showed that polycarboxylate superplasticizer synthesized under the following optimum conditions had the fluidity of cement paste 238 ram：the molar ratio of methacrylic acid/sodium methallyl- sulfonate/polyoxyethylene acrylate 56：12：32, ammonium persulfate as initiator 2.5 % by weight on the total amount of monomers, and reaction temperature of 80℃, reaction time of 6 hours. The water reducing ratio could reach 22. 5 % and the loss of concrete slump was little in 60 minutes, when adding 0.20 % superplasticizer in cement.