Effects of the chemical structure on the properties of polycarboxylate-type superplasticizer
Effects of the chemical structure on the properties of polycarboxylate-type superplasticizer
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DOI：
10.1016/s0008-8846(99)00230-6
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发表时间：
2000-02-01
影响因子：
11.4
通讯作者：
Matsuhisa, M
中科院分区：
文献类型：
--
作者：
Yamada, K;Takahashi, T;Matsuhisa, M
在分析侧链含聚氧乙烯（PEO）的聚羧酸系高效减水剂化学结构的基础上，研究了其对水泥颗粒的分散性能。分析了PEO侧链长度、主链聚合度、羧基和磺酸基等官能团的组成以及聚合物的纯度。它们作为分散剂的相对有效性进行了评估，在水泥净浆通过测量膏流动，塑性粘度，和剪切屈服应力在不同的水/水泥比（W/C）。虽然在高w/c时，化学结构对糊流动性的影响不显著，但在w/c低于25%时，它们变得显著。具有较长PEO侧链、较低主链聚合度和较高磺酸基含量的聚合物表现出较高的分散能力。水相中较高浓度的离子官能团延缓了水泥浆体的凝结。(C)2000爱思唯尔科技有限公司版权所有。
Based on the analysis of the chemical structure of polycarboxylate-type superplasticizers with polyoxyethylene (PEO) side chains, the dispersing properties for cement particles were investigated. Analyzed characteristics were the PEO side chain length, the degree of backbone polymerization, the composition of functional groups such as carboxylic and sulfonic groups, and the purity of polymers. Their relative effectiveness as dispersants was evaluated in cement paste by measuring paste flow, plastic viscosity, and shear yield stress at different water/cement ratios (w/c). Although the effects of chemical structure on the paste fluidity were not significant at high w/c, they became significant at w/c below 25%. Polymers with longer PEO side chains, lower degrees of backbone polymerization, and higher contents of sulfonic groups showed higher dispersing power. Higher concentrations of ionic functional groups in the aqueous phase delayed the setting of cement paste. (C) 2000 Elsevier Science Ltd. All rights reserved.