新型聚羧酸系减水剂大分子的合成与性能研究

Synthesis and Performance Study on New Macromolecule for Polycarboxylate Superplasticizer

以甲基丙烯酸、聚乙二醇为主要原料,以甲苯为带水剂、混酸为催化剂,对苯二酚为阻聚剂,通过酯化反应合成出甲基丙烯酸聚乙二醇单酯活性大单体。确定出最佳反应条件为:原料醇酸物质的量比为1:2,催化剂的用量为4%(以聚乙二醇的质量计),阻聚剂对苯二酚的用量为0.3%(以甲基丙烯酸的质量计),温度为95℃,反应时间为8h,合成出活性大单体的酯化率可高达86.4%。产品经酯化率的测定和IR结构表征,证明是目标产物。

Methacrylate polyglycol monoester was synthesized by condensation of polyethylene glycol and methacrylic acid with toluene as the water absorbent, mixed acid as the catalyst and hydroquinone as the inhibitor. The optimal conditions of esterification were obtained by the design that the molar rate of PEG to acrylic acid was 1：2, the reaction temperature was 95 ℃, the reaction time was 8h, the amount of catalyst was 4% according to the mass of PEG, the amount of inhibitor was 0.3% according to the mass of MAA. The rate of esterification was up to 86.4%. The structure of PEGA was characterized by FTIR and esterification rate.