MPEG侧链长度对聚羧酸超塑化剂吸附分散性能的影响

通过自由基聚合反应,本文制备了一系列具有不同侧链长度的梳型共聚物。研究了MPEG侧链长度对梳型共聚物分子构象的影响,并通过总有机碳分析(TOC)和净浆流动度测试对制得的不同侧链长度的聚羧酸梳型共聚物在水泥颗粒上的吸附分散性能进行了表征。结果表明:随着侧链MPEG长度的增加,共聚物在水泥颗粒上的吸附量会急剧降低;在MPEG-MAA与甲基丙烯酸(MAA)共聚体系中,按一定比例同时接人不同长度的MPEG侧链时,共聚物会表现出特殊的吸附规律;并且当侧链聚合度n_(EO)=22和n_(EO)=43按摩尔比1:2在共聚体系中进行接枝时,共聚物表现出最佳的分散性能。

Influence of the side chain lengths on the dispersion-adsorption performance of polycarboxylate superplasticizer

according to free-radicle polymerization,a series of comb-like copolymers were synthesized with different side chain lengths.Effect of side chain(MPEG)lengths on the molecular conformation was studied,and dispersion-adsorption performance of the comb-like copolymer on the cement were token by TOC and fluidity testing method.The result showed that the amount of polymer adsorption on cement rapidly decreases with increasing side chain length.In the system of polymerization of MPEG- MAA and MAA,the copolymer showed exceptive absorption law,when side chains(MPEG)with different lengths were grafted.The copolymer showed optimal dispersion performance when side chain with n(MPEG n_(EO)=22):n(MPPG n_(EO)=43)=1:2 were used.