聚羧酸系减水剂组成与结构对水泥颗粒表面电性质的影响

Influence of Composite and Structure of Polycarboxylate Superplasticizer on Surface Electric Properties of Cement Particles

以甲氧基聚乙二醇甲基丙烯酸酯(MAA-MPEG)和甲基丙烯酸(MAA)为主要原料,通过自由基共聚合反应制备了聚羧酸系减水剂,研究了减水剂的侧链聚合度、MAA/MAA-PEG比、分子量以及时间对水泥颗粒Zeta电位绝对值的影响。结果表明,随着侧链聚合度的增加,Zeta电位绝对值逐渐增大至趋向恒定;大分子量减水剂有利于增加水泥颗粒的Zeta电位绝对值;掺高分子量聚羧酸系减水剂试样的Zeta电位随时间的延长逐渐增加,而掺低分子量减水剂试样的则逐渐减小;增加减水剂分子中羧基单元的量可以增大水泥颗粒的初始Zeta电位绝对值,但随着时间的延长,Zeta电位绝对值逐渐下降。

Several polycarboxylate superpalsticizers （PC） were synthesized with methoxy polyethylene glycol methacry- late （MAA-MPEG） and rnethylacrylic acid （MAA） as the main raw materials through free radical copolymerization reaction. The influence of side chain, molecular weight and MAA/MPEG-MAA ratio on Zeta potential of cement particles was inves- tigated. It was found that with the increase of the side chain polymerization degree, the absolute value of Zeta potential in- creased gradually to tend to a constant, large molecular weight of water reducing agent was helpful to increase cement par- ticle Zeta potential absolute value, and Zeta potential of high molecular weight PC gradually increased with time elapsing, but with low molecular weight water reducing agent sample decreased, enlarging the amount of carboxyl unit of PC molecules increased cement particle initial Zeta potential absolute value, but with the extension of time, the absolute value of Zeta potential gradually declined.