Du Wei, Liu Quantao, Lin Runsheng, Su Xin
School of Material Science and Chemical Engineering, Ningbo University, Ningbo 315211, China.
State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
Materials (Basel). 2021 Mar 31;14(7):1725. doi: 10.3390/ma14071725.
Self-healing of cracks in cementitious materials using healing agents encapsulated in microcapsules is an intelligent and effective method. In this study, microcapsules were prepared by the melt-dispersion-condensation method using microcrystalline wax as the shell and E-51 epoxy resin as the healing agent. The effects of preparation process parameters and microcrystalline wax/E-51 epoxy resin weight ratio on the core content, particle size distribution, thermal properties, morphology, and chemical composition of microcapsules were investigated. The results indicated that the optimal parameters of the microcapsule were microcrystalline wax/E-51 epoxy resin weight ratio of 1:1.2, stirring speed of 900 rpm, and preparation temperature of 105 °C. The effects of microcapsules on pore size distribution, pore structure, mechanical properties, permeability, and ultrasonic amplitude of mortar were determined, and the self-healing ability of mortar with different contents of microcapsules was evaluated. The optimal content of microcapsules in mortars was 4% of the cement weight, and the surface cracks of mortar containing microcapsules with an initial width of 0.28 mm were self-healed within three days, indicating that microcapsules have excellent self-healing ability for cementitious materials.
使用包裹在微胶囊中的愈合剂实现水泥基材料裂缝的自愈合是一种智能且有效的方法。在本研究中，采用熔融分散冷凝法制备微胶囊，以微晶蜡为壳材，E-51环氧树脂为愈合剂。研究了制备工艺参数以及微晶蜡/E-51环氧树脂重量比对微胶囊的芯材含量、粒径分布、热性能、形态和化学成分的影响。结果表明，微胶囊的最佳参数为微晶蜡/E-51环氧树脂重量比为1:1.2、搅拌速度为900 rpm以及制备温度为105℃。测定了微胶囊对砂浆孔径分布、孔隙结构、力学性能、渗透性和超声振幅的影响，并评估了不同微胶囊含量的砂浆的自愈合能力。砂浆中微胶囊的最佳含量为水泥重量的4%，初始宽度为0.28 mm的含微胶囊砂浆的表面裂缝在三天内实现了自愈合，表明微胶囊对水泥基材料具有优异的自愈合能力。
