Microcapsule-Based Autonomous Self-Healing of Electrical Damage in Dielectric Polymers Induced by In Situ Generated Radicals

Dielectric polymers are playing important roles in electrical and electronic industries. However, aging under high electric stress is a main threat to the reliability of polymers. In this work, we demonstrate a self-healing method for electrical tree damage based on radical chain polymerization, which is initiated by in situ radicals that are generated during electrical aging. Acrylate monomers contained in microcapsules will be released and flow into hollow channels after the capsules are punctured by electrical trees. Autonomous radical polymerization of the monomers will heal the damaged regions, which is triggered by radicals resulting from polymer chain scissions. After optimizing the healing agent compositions by evaluating their polymerization rate and dielectric properties, the fabricated self-healing epoxy resins showed effective recovery from treeing in multiple aging-healing cycles. We also expect the great potential of this method to heal tree defects autonomously without the need to switch off operating voltages. This novel self-healing strategy will shed light on building smart dielectric polymers with its broad applicability and online healing competence.

Automated summary

In this study, a self-healing method for electrical tree damage based on radical chain polymerization is demonstrated, which is initiated by in situ radicals generated during electrical aging. Acrylate monomers contained in microcapsules will flow into hollow channels and autonomously polymerize to heal the damaged regions, triggered by radicals resulting from polymer chain scissions. The optimized self-healing epoxy resins showed effective recovery from treeing in multiple aging-healing cycles, highlighting the potential of this method for autonomous healing of tree defects without the need to switch off operating voltages. This novel self-healing strategy has broad applicability and online healing competence.