LDPE Composites With Self‐Healing of Modified SiO ₂ Particles and Inhibition of Electrical and Water‐Mixed Tree Branches

ABSTRACT Polymer insulation materials are affected by electromagnetic fields, mechanical stress, long‐term illumination, ambient temperature, and other operating conditions. These conditions can cause water trees and electrical trees damage, resulting in insulation failure. Self‐healing technology is the fundamental way to solve this problem. However, the effective self‐healing of water trees and electrical tree damage in insulating materials is extremely challenging. To solve this problem, a dual‐responsive self‐healing insulating material was prepared by doping 1% modified silicon dioxide, which made a breakthrough in the self‐healing and suppression of electrical trees and water trees, and doping modified silicon dioxide particles enhanced intermolecular interaction and improved material mechanics and insulation performance. When electrical and water‐mixed tree branches aging occurs, oligomers generated by grafted siloxane groups and acrylate groups can effectively fill the pores of the electrical and water trees on top of the physical filling of the pores by silicon dioxide particles. The performance of the cured material is close to that of the pure sample. This method realizes the dual‐response self‐healing of the insulation material after the aging of the electro‐hydro mixed tree, which provides a new way to repair polyethylene cable insulation and has great potential in practical applications.