基于EPEG单体的两性聚羧酸减水剂的合成及抗泥性能

Synthesis and mud resistance of amphoteric polycarboxylate superplasticizer based on EPEG monomer

以活性较高的新型大单体乙二醇单乙烯基聚乙二醇醚(EPEG)与丙烯酸(AA)、甲基丙烯磺酸钠(SMAS)、丙烯酰氧乙基三甲基氯化铵(DAC)等进行水溶液自由基聚合反应,合成了抗泥型聚羧酸减水剂PCE-ES和PCE-ESD。采用FTIR、1H NMR进行结构表征,通过水泥净浆流动度测试了减水剂的抗泥性能,并采用XRD和XPS探究不同减水剂与蒙脱土、水泥之间的作用机理。结果表明,当减水剂的掺量为水泥质量的0.25%,蒙脱土掺量3%时,掺PCE-ES和PCE-ESD有一定的抗泥性,且PCE-ESD的抗泥性能更佳;XRD表明,蒙脱土吸附PCE-ES、PCE-ESD的层间距变化不大,说明蒙脱土对减水剂的负面作用一定程度上有所降低,从而提高了减水剂对水泥的分散能力。

EPEG-Based mud-resisitant polycarboxylate superplasticizer PCE-ES and PCE-ESD were synthesized by aqueous free radical polymerization reaction of a new type of macromonomer ethylene glycol monovinyl polyethylene glycol ether(EPEG),acrylic acid(AA),sodium methacrylate sulfonate(SMAS)and acryloyloxyethyl trimethyl ammonium chloride(DAC)as macromonomer,and the structure of the target product was analyzed and characterized by FTIR and 1H NMR,the mud resistance of the water reducing agent was tested by the net cement slurry flow rate,and the mechanism of the interaction between different water reducing agents and montmorillonite and cement was investigated by XRD and XPS.The results show that when the water reducing agent is 0.25% by mass of cement and 3%by mass of montmorillonite,PCE-ES and PCE-ESD have certain mud resistance,and PCE-ESD has better mud resistance;the XRD results showed that the layer spacing of PCE-ES and PCE-ESD adsorbed by montmorillonite did not change much,indicating that the negative effect of montmorillonite on water reducing agent was reduced to some extent,thus improving the dispersing ability of water reducing agent on cement.