低分子量磷酸基减水剂的合成、性能及应用研究

Synthesis,Properties and Application of Low Molecular Weight Phosphate Group Water Reducer

以聚乙二醇单甲醚(MPEG-2000)作为主链,磷酸作为末端吸附基团,合成了低分子磷酸基减水剂PM-2,分析了红外吸收光谱、凝胶渗透色谱,并研究了PM-2的分散性能、黏土敏感性、水泥对其的吸附性、对水泥水化热的影响及在混凝土中的应用效果。结果表明:与聚羧酸减水剂PCE-1相比,所制备的PM-2的分散性保持能力强,黏土敏感性低,水泥颗粒对其的吸附量少,同时具有一定的延缓水泥水化的效果,但减水效果相对较低;通过PCE-1和PM-2复配可以显著提升混凝土的坍落度及其保持能力,且不会降低混凝土强度。

A low molecular weight phosphate based water reducer was synthesized by using polyethylene glycol monomethyl ether(MPEG-2000)as the main chain and phosphoric acid as the terminal adsorption group.The molecular structure and molecular weight were determined by IR and GPC.The dispersion property of PM-2,clay sensitivity,adsorption of cement,influence on cement hydration heat and application effect in concrete were studied.The results show that,compared with polycarboxylic acid water reducer PCE-1,the prepared PM-2 has strong dispersion retention ability,low clay sensitivity,less adsorption capacity of cement particles,and has a certain effect of delaying cement hydration,but the water reducing effect is relatively low.By mixing PCE-1 and PM-2,the concrete slump and its retention capacity can be significantly improved without reducing the concrete strength.