Self-Healing Properties of XLPE Composites Under Microcapsules Gradient Distribution

Cross-linked polyethylene (XLPE) insulation materials produce water tree aging under the combined action of moisture and electric field for a long time, resulting in a decline in insulation performance and a serious threat to the safety of power system operation. In view of the above problems, a three-layer shell–core microcapsule with siloxane as a repair agent was designed in this article, and it was distributed in the XLPE matrix material in a gradient manner to realize the self-healing of the material to water tree aging. The results showed that the microcapsules had good morphology. When the doping concentration of the microcapsules is low (1.0 wt%), it can also have an excellent water tree aging repair effect on the basis of ensuring the original insulation performance of XLPE. The repair effect of microcapsules/XLPE composites with gradient distribution is better than that of microcapsules/XLPE composites with uniform distribution, which solves the problem of low repair efficiency of uniform distribution and has a good research prospect in practical application.