超支化型聚羧酸系减水剂的制备

Preparation of hyperbranched polycarboxylic superplasticizer

以溴端基超支化聚(胺-酯)、丙烯酸、单甲氧基封端烯丙基聚乙二醇(APEG-27)为原料,采用ATRP法制备出了一种新型的超支化型聚羧酸系减水剂(HPC),并用红外、核磁对产品进行了表征。水泥净浆流动性试验表明该种超支化型减水剂具有较好的分散性;表观吸附量的测试验证了超支化型减水剂可以有效地吸附在水泥粒子表面;采用微电泳仪测试了Zeta电位,其测试结果显示:空间位阻效应为该种超支化型减水剂的主要分散机理。

Hyperbranched polycarboxylic superplasticizer （HPC） was synthesized by ATRP from bromo-terminated hyperbranched poly （amine-ester）,acrylic acid, monomethoxy-capped polyethylene glycol allyl and characterized by FTIR spectra and 1 HNMR.The dispersing effec- tiveness of HPC was assessed by flow of paste.The amount of superplasticizers adsorbed on cement was tested and the result showed the novel hyperbranched polycarboxylic superplasticizer could significantly adsorbed on the surface of cement particles,Zeta potential measurements using the electroacoustic method indicate steric repulsion between the cement particles carrying adsorbed polymer molecules is the main mechanism for dispersion.