论文部分内容阅读
以阴、阳离子功能性单体(AA、DMC)与聚乙二醇单甲醚丙烯酸酯大分子单体(MPEGAA)主要原料,采用水溶液自由基聚合法,合成了一种P(AA-co-DMC)/MPEGAA两性型聚羧酸超塑化剂。通过FTIR、1H NMR分析了所合成两性型聚羧酸超塑化剂分子结构,结果表明已得到预期结构的P(AA-co-DMC)/MPEGAA两性型聚羧酸超塑化剂。同时,研究了水泥净浆流动度及聚合反应转化率随n(AA)∶n(DMC)∶n(MPEGAA)、引发剂用量w(K_2S_2O_8)(以占单体总质量计,下同),聚合反应温度Tcr,反应恒温时间t_(cr)的变化规律,结果表明:n(AA)∶n(DMC)∶n(MPEGAA)=0.50∶0.10∶0.25,w(K2S2O8)=5.0%,tcr=60℃,t_(cr)=3 h是制备P(AA-co-DMC)/MPEGAA两性型聚羧酸超塑化剂的最佳工艺条件。并测定了添加质量分数为2.0%的两性型聚羧酸超塑化剂混凝土性能,结果显示:以最佳合成工艺条件制得的P(AA-co-DMC)/MPEGAA两性型聚羧酸超塑化剂,在混凝土中具有优越分散保持性能和较高早期强度性能。
A new kind of P (AA-co-AA) was synthesized by free radical polymerization of anionic and cationic functional monomers (AA, DMC) and polyethylene glycol monomethyl ether acrylate macromer (MPEGAA) DMC) / MPEGAA amphoteric polycarboxylate superplasticizer. The molecular structure of the amphoteric polycarboxylate superplasticizer was analyzed by FTIR and 1H NMR. The results showed that P (AA-co-DMC) / MPEGAA amphoteric polycarboxylate superplasticizer with the expected structure was obtained. In the meantime, the fluidity of cement paste and the conversion rate of polymerization reaction were investigated with n (AA): n (DMC): n (MPEGAA), initiator amount w (K 2 S 2 O 8) (DMC): n (MPEGAA) = 0.50: 0.10: 0.25, w (K2S2O8) = 5.0%, tcr = 60 ℃, t_ (cr) = 3 h is the optimum process conditions for the preparation of P (AA-co-DMC) / MPEGAA amphoteric polycarboxylate superplasticizer. And the properties of the amphoteric polycarboxylate superplasticizer concrete with addition of 2.0% of mass fraction were determined. The results showed that P (AA-co-DMC) / MPEGAA amphoteric polycarboxylate with the best synthetic conditions Plasticizers, in the concrete has excellent dispersion to maintain performance and high early strength properties.