不同磷酸酯单体的EPEG型聚羧酸减水剂的制备及抗泥性能

Preparation and anti-mud function of EPEG polycarboxylate superplasticizers with different phosphate monomers

以乙二醇单乙烯基聚乙二醇醚(EPEG)为大单体,丙烯酸(AA)为小单体,2-羟乙基甲基丙烯酸酯磷酸酯(HEMAP)或封端酰胺磷酸酯(CAP)为功能单体,采用水溶液自由基共聚法合成了两种EPEG型抗泥型聚羧酸减水剂PCE-EP_(1)和PCE-EP_(2)。采用FTIR、^(1)HNMR对减水剂结构进行了表征,通过水泥净浆流动度测试了合成的减水剂对水泥的分散性能以及抗泥性能,并结合XRD和XPS探究了减水剂与水泥、蒙脱土之间的作用机理。结果表明,当减水剂的折固掺量为水泥质量0.2%,蒙脱土替换2%水泥时,掺PCE-EP_(1)和PCE-EP_(2)的抗泥性能优于PCE-E(不加磷酸酯单体的产物)。XRD结果说明,蒙脱土与减水剂PCE-EP_(1)、PCE-EP_(2)不存在插层吸附,可以一定程度上降低蒙脱土对减水剂的负面影响,从而提高该减水剂对含蒙脱土水泥的分散能力。

Two anti-mud ethylene glycol monovinyl polyethylene glycol ether(EPEG)polycarboxylate superplasticizers PCE-EP_(1)and PCE-EP_(2)were synthesized via free radical copolymerization of large monomer,minor monomer acrylic acid(AA),functional monomers 2-hydroxyethyl methacrylate phosphate phosphate(HEMAP)or terminated amide phosphate ester(CAP)in aqueous solution,and characterized by FTIR and^(1)HNMR for structural analysis.The dispersion and anti-mud performance of the synthesized water-reducing agent added to cement were then tested by the fluidity of cement paste,followed by exploration on the interaction mechanism between water-reducing agent and cement and montmorillonite through XRD and XPS.The results showed that when the content of water reducing agent was 0.2%of cement mass with 2%of cement replaced by montmorillonite,PCE-EP_(1)and PCE-EP_(2)displayed certain anti-mud function.Moreover,XRD results showed that there was no intercalation adsorption between montmorillonite and water-reducing agents PCE-EP_(1)and PCE-EP_(2),which could reduce the negative influence of montmorillonite on water-reducing agent to some extent,thus improving the dispersing ability of the water-reducing agent in cement containing soil.