磷酸酯型聚羧酸减水剂的合成及其对矿粉适应性研究

Synthesis of polycarboxylate superplasticizer containing phosphate group and its adaptability to mineral powder

以异戊烯醇基聚乙二醇、丙烯酸、甲基丙烯酸羟乙酯磷酸酯为聚合单体,甲基丙烯酸磺酸钠为链转移剂,通过自由基水溶液聚合法合成磷酸酯型聚羧酸减水剂PCE-Y-HEMAP。采用FTIR、GPC、TOC和TGA等对磷酸酯型减水剂与含有白云母、钠长石矿物石粉进行适应性研究。FTIR、GPC分析表明,成功合成了一种HEMAP改性的新型减水剂。水泥净浆流动度试验结果表明,PCE-Y-HEMAP具有良好的分散性和分散保持性。TGA、TOC分析表明,PCE-Y-HEMAP对含钠长石粉水泥分散保持性较好的原因是减水剂分子吸附在钠长石骨架折陷结构之间吸附性较强、吸附量较少。另外,吸附在钠长石表面的减水剂由于空间位阻作用,对水泥颗粒有一定的分散作用,适应性较好。

Polycarboxylate superplasticizer PCE-Y-HEMAP containing phosphate group was synthesized by isoprenyloxypoly(ethylene glycol)ether macromonomers,acrylic acid(AA)and 2-hydroxylethyl methacrylate phosphate(HEMAP)as polymerization monomer and sodiummethylallyl sulfonate(MAS)as chain transfer agent by aqueous solution radical polymerization.FTIR,GRC,Total organic carbon analyzers(TOC)and thermal gravimetric analysis(TGA)were used to study the adaptability of phosphate group polycarboxylate superplasticizer between mineral powder containing muscovite or albite.The results of FTIR and GPC showed that a new polycarboxylate superplasticize was synthesized by modification of HEMAP.The flow degree loss test of cement paste prove that PCE-Y-HEMAP has good dispersion and dispersion retention performance.TGA and TOC studies show that the fluidity of the sodium feldspar powder and PCE-Y-HEMAP is better because the adsorbability of the water reducing agent adsorbed between the sodium feldspar framework and the structure of the sodium feldspar is stronger.Besides,because of steric hindrance,the polycarboxylate superplasticizer of albite has a certain dispersing effect on cement particles,which makes the adaptability of albite and polycarboxylate superplasticizer better.