Self‐Healing Properties of <scp>XLPE</scp> Composites Under Microcapsules Gradient Distribution

ABSTRACT 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.