疏水烷基酯侧链对聚羧酸系减水剂分散及保坍性能的影响

发布时间：2019-05-09 22:58

【摘要】：为了研究聚羧酸系减水剂(PCA)分子结构中疏水侧链对新拌混凝土坍落度及其损失的影响,以马来酸酐(MA)、异戊烯醇聚氧乙烯醚(TPEG)和丙烯酸烷基酯为原料,过硫酸铵为引发剂,通过自由基聚合合成了4种不同疏水侧链长度(疏水侧链含碳个数分别为4、8、12和18)的聚羧酸系减水剂。通过水泥净浆流动度、流动性损失等指标检验了聚羧酸系减水剂的分散性能及保坍性能,结果表明随着疏水侧链长度的增加,聚羧酸系减水剂的分散性能逐渐提高,保坍性能有所改善。吸附量和zeta电位测试结果解释了这种现象的原因,随着疏水侧链长度的增加,水泥颗粒表面zeta电位绝对值逐渐增加,水泥颗粒表面上的持续吸附能力逐渐增强。
[Abstract]:In order to study the effect of hydrophobic side chain on the slump and loss of fresh concrete, the effect of hydrophobic side chain on the slump and loss of fresh concrete was studied by using (MA), isopentenol polyoxylene ether (TPEG) and alkyl acrylic ester as raw materials. Four kinds of polycarboxylic acid water reducer with different hydrophobic side chain length (the number of carbon in hydrophobic side chain was 4, 8, 12 and 18, respectively) were synthesized by free radical polymerization with ammonium persulfate as initiator. The dispersion performance and slump retention performance of polycarboxylic acid series superplasticizer were tested by the indexes of mobility and flow loss of cement paste. The results showed that with the increase of hydrophobic side chain length, the dispersion performance of polyCarboxylic acid series water reducer was gradually improved. The results showed that the dispersion performance of polyCarboxylic acid series water reducer was gradually improved with the increase of hydrophobic side chain length. The slump preservation performance has been improved. The results of adsorption capacity and zeta potential test explain this phenomenon. With the increase of hydrophobic side chain length, the absolute value of zeta potential on the surface of cement particles increases gradually, and the continuous adsorption capacity on the surface of cement particles increases gradually.
【作者单位】：中国建筑材料科学研究总院绿色建筑材料国家重点实验室;
【基金】：国家“十二五”科技支撑资助项目(2011BAE27B03) 中国建筑材料科学研究总院青年科学基金资助项目(YA-485)
【分类号】：TU528.042.2

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