兩性離子共聚合物合成以及對水泥質材料流動性的可行性評估

Abstract

添加強塑劑於混凝土中，可增加混凝土的工作性。本研究先利用丙烯酸二甲胺乙酯與氯醋酸鈉合成出DAAE單體。接著由2-丙烯醯胺-2-甲基丙烷磺酸(AMPSA)、甲基丙烯酸(MAA)與DAAE單體以自由基聚合方式，反應得到共聚物PAMD。合成之DAAE與PAMD以FT-IR與1H-NMR鑑定其結構，並以電位滴定儀測定共聚物單體比例。探討PAMD的單體比例與分子量對水泥漿流動性的影響，並以共聚物對水泥粒子吸附行為與表面電位來說明。 研究結果顯示，添加PAMD (AMPSA/MAA/DAAE = 6/10/1，Mw=1.1×105) 的水泥漿有最好的迷你坍度與坍度維持性，飽和劑量約為0.2wt%，效果優於商用強塑劑HP100 (羧酸系)與HPC1000 (磺酸系)。

Superplasticizer can improve the workability of concrete. In this research, the DAAE monomer was prepared from 2-(Dimethylamino) ethyl acrylate and sodium chloroacetate. The copolymer (PAMD) was prepared from 2-acrylamido-2-methylpropane sulfonic acid (AMPSA), methacrylic acid (MAA), and the monomers (DAAE) by free-radical polymerization. The prepared monomer (DAAE) and PAMD were confirmed by FT-IR and 1H-NMR spectra. The monomer ratio of copolymer was determined by the potentiometric titration method. The effects of the monomer ratio, and molecular weight of copolymer on the fluidity of cement pastes were investigated﹔The results was explained by the adsorption behavior of copolymer on the cement particles and zeta potential. The results indicate that the cement pastes containing PAMD ( AMPSA / MAA /DAAE = 6 / 10 / 1, Mw=1.1×105) shows the highest mini-slump and the best mini-slump retention, the saturation dosage was about 0.2 wt%, and the result were better than those of HP100 (carboxylate-based) and HPC1000 (sulfonate-based).