Based on the reversible diels-alder reaction of microcapsule / XLPE composites self-healing electrical and water mixed tree branches

A microcapsule/XLPE composite material based on reversible Diels-Alder(DA) reaction was designed to solve the problem of electro-hydro hybrid tree aging in cross-linked polyethylene (XLPE) cables during long-term operation. Light-water dual-responsive microcapsules were prepared by in-situ polymerization using hyperbranched polysiloxane containing furan functional groups and linear polysiloxane containing furan and maleimide functional groups introduced by C C covalent bond as core materials and urea-formaldehyde resin as wall materials. A series of composites was prepared by regulating the doping concentration of microcapsules, and their insulation properties were tested. The effect of the doping content of microcapsules on the properties of materials was analyzed, and the multiple self-healing mechanism of microcapsule/XLPE composite was revealed. The results show that when the microcapsule doping concentration is 1 wt%, the composite material can self-heal while maintaining the intrinsic insulation performance of XLPE. Under the condition of thermal triggering, the dynamic reconstruction of the reversible bond enables the material to achieve dual repair of water tree and electrical tree damage, and maintains more than 80 % of the insulation performance after three times of damage-repair, which provides a new strategy for the intelligent design and life extension of high voltage cable insulation materials.