Fang Yunhui, Chen Zhanhua, Yan Dongming, Ke Yuliang, Ma Xiuxing, Lai Junying, Liu Yi, Li Geli, Zhang Xiaofang, Lin Zhijun, Wang Zhaopeng
KZJ New Materials Group Co., Ltd., Xiamen 361101, China.
Polytechnic Institute, Zhejiang University, Hangzhou 310015, China.
Materials (Basel). 2023 Jul 4;16(13):4823. doi: 10.3390/ma16134823.
Polycarboxylate ether (PCE) with different main chain structures was prepared by aqueous solution free radical polymerization using unsaturated acids containing sulfonic acid groups, acrylamide groups, and carboxyl groups and isoprenyl polyoxyethylene ether (IPEG). The molecular structure was characterized by infrared spectroscopy and gel chromatography, while adsorption, dispersion, and hydration properties were studied using a total organic carbon analyzer, rheometer, and isothermal microcalorimeter, respectively. The results show that the adsorption process of PCE on cement particles is spontaneous physical adsorption. The adsorption forces are mainly electrostatic interaction, and hydrogen bonding. The introduction of sulfonic acid groups and polycarboxylic acid groups reduces the initial adsorption amount of PCE but can accelerate the adsorption rate of PCE on cement and increase the adsorption amount at the adsorption equilibrium. The introduction of acrylamide groups in the PCE main chain is beneficial to the initial dispersion of PCE and can reduce the plastic viscosity of cement slurry. PCE can delay the hydration of cement. The introduction of acrylamide groups and dicarboxylic acid groups in the PCE main chain helps prolong the induction period of cement hydration, while the introduction of sulfonic acid groups is not conducive to its retarding effect.
以含有磺酸基、丙烯酰胺基和羧基的不饱和酸与异戊烯基聚氧乙烯醚（IPEG）为原料，通过水溶液自由基聚合法制备了具有不同主链结构的聚羧酸醚（PCE）。采用红外光谱和凝胶色谱对其分子结构进行了表征，同时分别使用总有机碳分析仪、流变仪和等温微量热仪研究了其吸附、分散和水化性能。结果表明，PCE在水泥颗粒上的吸附过程为自发物理吸附。吸附作用力主要为静电相互作用和氢键。磺酸基和聚羧酸基的引入降低了PCE的初始吸附量，但能加快PCE在水泥上的吸附速率，并增加吸附平衡时的吸附量。PCE主链中丙烯酰胺基的引入有利于PCE的初始分散，并能降低水泥浆体的塑性粘度。PCE能延缓水泥的水化。PCE主链中丙烯酰胺基和二元羧酸基的引入有助于延长水泥水化的诱导期，而磺酸基的引入不利于其缓凝效果。
