In this study, the effect of both main and side chain length changes of the admixtures on some properties of cementitious systems were investigated. Three different polycarboxylate‐ether‐based water‐reducing admixtures (WRA) having constant molecular weights and different main and side chain lengths were synthesized. Single type of raw material and carboxylate functional group were used in all WRAs. The molecular weights, free nonionic contents, and anionic/nonionic ratios of the admixtures were kept constant. Test results showed that degree of fluidity was observed in cement paste and mortar mixtures in case the admixture main and side chain length is more or less than a critical value. This negative effect is thought to be due to the weakening of the adsorption ability by the chain length change of the admixtures, the being tendency of polymers to intertwine and the adsorbing of admixture on several cement particles simultaneous. Admixtures having excessive long or short main chain and side chain improved the time‐dependent slump‐flow retention of the mortar mixtures. The admixtures with short main and side chains had insufficient adsorption ability and the admixture with excessive long main and side chains had the interlacing risk of polymers. In both cases, time‐dependent behavior improved because the amount of free admixture in solution increased. The change in the chain lengths of the WRAs affected the 1‐day compressive strength of the mortar mixtures.

中文翻译：

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聚羧酸酯基减水剂的主链和侧链长度变化对胶结体系的新鲜状态和力学性能的影响

在这项研究中，研究了混合物的主链和侧链长度变化对胶凝体系某些性能的影响。合成了三种分子量恒定，主链和侧链长度不同的聚羧酸酯醚减水剂（WRA）。所有WRA中均使用单一类型的原料和羧酸盐官能团。混合物的分子量，游离非离子含量和阴离子/非离子比率保持恒定。测试结果表明，在掺和料的主链和侧链长度大于或小于临界值的情况下，在水泥浆和砂浆混合物中观察到流动性。认为这种负面影响是由于混合物链长的变化导致吸附能力减弱，聚合物相互缠绕的趋势，以及混合物同时吸附在几种水泥颗粒上的趋势。主链和侧链过长或过短的掺混料可改善砂浆混合物随时间变化的坍落度保持力。主链和侧链短的混合物吸附能力不足，主链和侧链过长的混合物具有聚合物的隔行风险。在这两种情况下，时间依赖性的行为都得到了改善，因为溶液中游离混合物的数量增加了。WRA链长的变化影响了灰浆混合物的1天抗压强度。主链和侧链过长或过短的掺混料可改善砂浆混合物随时间变化的坍落度保持力。主链和侧链短的混合物吸附能力不足，主链和侧链过长的混合物具有聚合物的隔行风险。在这两种情况下，时间依赖性的行为都得到了改善，因为溶液中游离混合物的数量增加了。WRA链长的变化影响了灰浆混合物的1天抗压强度。主链和侧链过长或过短的掺混料可改善砂浆混合物随时间变化的坍落度保持力。主链和侧链短的混合物吸附能力不足，主链和侧链过长的混合物具有聚合物的隔行风险。在这两种情况下，时间依赖性的行为都得到了改善，因为溶液中游离混合物的数量增加了。WRA链长的变化影响了灰浆混合物的1天抗压强度。