阳离子聚合物改善聚羧酸减水剂抗泥性能及作用原理

Anti-Clay Property and Action Principle of Polycarboxylate Superplasticizer Improved by Cationic Polymer

以不饱和季铵盐单体与不饱和非(阴)离子单体进行水溶液自由基共聚,合成了系列阳离子聚合物型牺牲剂(CSA)。采用水泥净浆流动度来评价牺牲剂对加蒙脱土水泥中聚羧酸减水剂(PCE)分散性能的影响。结合有机碳吸附、热重分析、X射线衍射等测试手段,不仅考察了聚合单体比例、季铵盐单体种类、非(阴)离子单体种类对牺牲剂作用效果的影响,确定了三甲基烯丙基溴化铵-丙烯酰胺(ATMA-AM2:1)为最佳结构,同时也探明了其作用原理。加入ATMA-AM(2:1)后,有效阻止了PCE分子聚醚侧链进入到蒙脱土层间,显著降低了PCE分子在蒙脱土上的吸附量,增加了其在水泥颗粒上的有效吸附,掺蒙脱土水泥中PCE的流动度由156 mm提升至225 mm,显著改善了蒙脱土对PCE分散性能带来的负面影响。

A series of cationic sacrificial agents(CSA) were synthesized via free radical copolymerization of unsaturated quaternary ammonium salt monomer and unsaturated nonionic(anion) monomer. The effect of sacrificial agent on the dispersion of polycarboxylate superplasticizer in cement mixed with montmorillonite(MMT) was evaluated via the fluidity of cement paste. Also, the effects of monomer polymerization ratio, quaternary ammonium salt monomer type and nonionic(anionic) monomer type on the action effect of the sacrificial agent were investigated by organic carbon analysis, thermogravimetry, X-ray diffraction, and scanning electron microscopy. Trimethyl allyl ammonium bromide-acrylamide(ATMA-AM 2:1) was determined as an optimum structure, and its action mechanism was also analyzed. The fluidity of PCE in cement paste mixed with MMT increases from 156 mm to 225 mm at 1.0% of ATMA-AM(2:1). The adsorption capacity of PCE on MMT and the holes on the surface of MMT all reduce, thus effectively preventing the polyether side chain of PCE molecule from entering the interlayer of MMT and enhancing MMT effect on the dispersion property of PCE.