聚羧酸系减水剂大分子单体的无溶剂法制备

以聚乙二醇单甲醚1200(MPEG1200)与丙烯酸(AA)为原料,在无溶剂条件下进行酯化法,成功制备了丙烯酸聚乙二醇单甲醚1200酯(AA-MPEG1200)。经正交实验优选出最佳合成工艺条件如下:酸醇摩尔比为3∶1,催化剂对甲苯磺酸用量为MPEG1200和AA总质量的2%,阻聚剂对苯二酚用量为AA质量的2%,反应时间为7 h,反应温度为125℃。此条件下酯化率达99.72%。此外,对所合成的AA-MPEG1200大单体进行了红外表征。以该大单体合成的聚羧酸减水剂具有良好的分散性和保塑性。

Solvent-free Synthesis of Polycarboxylate Water Reducer Intermediate Macromonomer

Acrylic acid methoxypolyethylene glycol 1200 ester （AA-MPEGI200） as was successfully synthesized by solvent-free reaction of methoxypolyethylene glycol 1200 （MPEGI200） and acrylic acid （AA）. By orthogonal experiment, the optimum synthetic conditions for the macromonomer were obtained as follows： the molar ratio of AA to poly2 MPEG1200 was 3：1; the amount of toluene-p-sulfonic acid as catalyst was 2 % according to the mass of MPEG 1200 and AA; the amount of bydroquinone as polymerization retarder was 2 % according to the mass of AA; and the reaction time was 7 h and the reaction temperature was 125 ℃. Under the optimum synthetic conditions, the percentage of esterification could he up to 99.72 %. The AA-MPEG1200 macromonomer was also characterized by infrared spectrum. In addition, the polycarboxylate water reducer synthesized by this macromonomer displays good dispersability and fluidity keeping ability.