Research on the microstructure formation of polyacrylate latex modified mortars
Research on the microstructure formation of polyacrylate latex modified mortars
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DOI：
10.1016/j.conbuildmat.2013.06.016
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发表时间：
2013-10
影响因子：
7.4
通讯作者：
Ye Tian;Xianyu Jin;N. Jin;Ruoyi Zhao;Zongjin Li;Hongyan Ma
中科院分区：
文献类型：
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作者：
Ye Tian;Xianyu Jin;N. Jin;Ruoyi Zhao;Zongjin Li;Hongyan Ma
研究了聚丙烯酸酯(PA)乳液改性水泥基材料从混合到硬化的微观结构形成过程。由于PA颗粒与孔溶液中的钙离子发生化学反应，PA聚合物吸附在水泥颗粒或水化产物上，不能均匀分散在水泥砂浆中。因此，PA聚合物应该以不同的形态存在于水泥砂浆中。PA改性砂浆的早期力学性能低于未改性砂浆，但抗压强度和断裂能有较大幅度的提高。研究发现，PA聚合物的掺入会细化水泥砂浆的小孔，但会诱导水泥砂浆产生大孔。扫描电子显微镜和能谱分析表明，PA聚合物存在于PA改性砂浆中的某些部位，这可称为聚合物改性的局部化。将PA聚合物对水泥基材料的物理和化学影响纳入了一个改进的模型。
The microstructure forming process of polyacrylate (PA) latex modified cement-based materials was investigated from mixing to hardening. Owing to the chemical reaction between PA particles and calcium ions in the pore solution, PA polymer will not uniformly disperse in cement mortar due to its adsorption on cement particles or hydrates. As a result, PA polymer should exist in cement mortars through different morphologies. The early age mechanical properties of PA modified mortars are lower than those of unmodified mortars, while a rapid progress of the compressive strength and fracture energy can be recognized from the PA modified mortars. It was found that PA polymer addition will refine the small pores but induce big pores to cement mortar. SEM and EDX analysis proves that PA polymer is localized at some places within PA modified mortar which can be named as the localization of polymer modification. The physical and chemical influence of PA polymer on cement-based materials was integrated into an improved model.