梳型聚羧酸盐高效减水剂的合成及性能

Synthesis of water-reducing agent of polycarboxylic acid concrete

通过自制单体丙烯酸聚乙二醇单酯(PA)、丙烯基磺酸钠(SAS)与马来酸酐(MA),在过硫酸盐的引发下共聚,合成了梳型聚羧酸盐高效减水剂;分析了反应单体的摩尔配比、引发剂质量分数、反应时间、反应温度等因素对减水剂性能的影响,得到了最佳合成工艺条件,即单体摩尔配比MA∶PA∶SAS为1∶3∶2.4,单体质量分数为1.0%的引发剂(K2S2O8),反应温度为85℃,时间为5h;采用红外光谱对产品进行了表征,并测试了该减水剂进行水泥净浆流动度等性能.结果表明:合成的减水剂具有良好的分散性能,对水泥净浆有缓凝保坍作用,是一种高性能混凝土减水剂,在混凝土中,质量分数为0.6%时,减水率可达33.6%.

Water reducing copolymer of sodium acryl-sulfate, Maleic acid, and methyl acrylate with the polyoxyethylene group chain was synthesized in the aqueous system by the initiation of per-sulfate. the study was also carried out about the influencing factors of content molar ratio, the content of initiator, the reaction time and the reaction temperature, etc. The optimum condition of synthesis was revealed:the rate of monomers MA∶PA∶SAS=1∶3∶2.4, temperature 85 ℃, time 5 h, the reaction is 1% K_2S_2O_8. The product was characterized and analyzed by FT-IR. The product obtained PC showed good dispersion, it exerted retarding effects on cement paste and the ability of keeping the fluidity for a long time. When 0.6% PC was added to the concrete, the water-reduction reached 33.6%, which guarantees an excellent water reducing agent to concrete.