Tan Xiaoyong, Zhang Jiupeng, Guo Dong, Sun Guoqing, Zhou Yingying, Zhang Wenwu
Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang)an University, Xi)an, Shaanxi 710064, China.
T. Y. Lin International Engineering Consulting (China) Co., Ltd., Chongqing 401120, China.
J Nanosci Nanotechnol. 2020 Mar 1;20(3):1554-1566. doi: 10.1166/jnn.2020.17338.
Cracks are the main challenges for asphalt pavement, which should be timely repaired. One of the most commonly used repairing methods is to fill the binding materials into cracks, but the repeated repairing ability is insufficient. The self-healing microcapsule technologies provide the potentials for enhancing the repeated repairing ability of filling materials. Therefore, the microcapsule core material was selected from sunflower oil in this study, and the capsular wall material was selected from melamine-urea-formaldehyde resin, which was used to prepare the microcapsule by using polymerization method. Three kinds of microcapsules with different particle sizes were prepared by adjusting the emulsifier dosage and core wall ratio. The microstructure, molecular structure, thermal stability, and dispersion features were further studied, and the effects of microcapsules with different particle sizes on the repeated repairability of the filling materials were evaluated via the fatiguerepair-fatigue test. In addition, the traditional regenerative microcapsules were compared to determine the optimal particle size range for sunflower oil microcapsules. According to the experimental research, it was thus concluded that the emulsion droplet size distribution was most concentrated when the emulsifier content was 0.7%; and when the core-wall ratio was 1.3:1, the microcapsules had uniform particle size and good dispersion effect. When the microcapsule emulsification rate was 900 rpm and microcapsule content was 2%, then the repeated repair effect for the microcapsule crack filling materials was optimal. The sunflower oil type microcapsule therefore meets the filling temperature requirement for the filler.
裂缝是沥青路面面临的主要挑战，需要及时修复。最常用的修复方法之一是向裂缝中填充粘结材料，但重复修复能力不足。自修复微胶囊技术为提高填充材料的重复修复能力提供了潜力。因此，本研究选用向日葵油作为微胶囊芯材，选用三聚氰胺-尿素-甲醛树脂作为囊壁材料，采用聚合方法制备微胶囊。通过调整乳化剂用量和芯壁比制备了三种不同粒径的微胶囊。进一步研究了其微观结构、分子结构、热稳定性和分散特性，并通过疲劳-修复-疲劳试验评估了不同粒径微胶囊对填充材料重复修复性能的影响。此外，与传统的再生微胶囊进行了比较，以确定向日葵油微胶囊的最佳粒径范围。根据实验研究得出，当乳化剂含量为0.7%时，乳液滴粒径分布最集中；当芯壁比为1.3:1时，微胶囊粒径均匀，分散效果良好。当微胶囊乳化速率为900 rpm且微胶囊含量为2%时，微胶囊裂缝填充材料的重复修复效果最佳。因此，向日葵油型微胶囊满足了填充料的填充温度要求。
