Rapid Self-Healing, Reprocessable, and Degradable Epoxy Resins via Imine-Disulfide Dynamic Bonds for Electrical Insulation

Abstract

Epoxy resins are indispensable in electrical and structural applications due to their excellent mechanical strength and insulating properties. However, their permanently cross-linking network structure renders them irreparable, unrecyclable, and nondegradable, severely limiting their sustainability. In this study, we report a dynamic epoxy resin system constructed by integrating disulfide and imine dynamic covalent bonds into the cross-linking network. A vanillin-derived epoxy monomer was synthesized and cured with a disulfide-containing diamine to prepare a reconfigurable thermoset (1VPEP), which exhibits excellent insulation performance, favorable thermal stability, and mechanical strength. Owing to its dynamic characteristics, the material possesses a range of advanced functionalities. It enables efficient scratch healing within 10 min at 160 °C and also exhibits a certain degree of recovery from electric-treeing damage in power equipment. Additionally, the material shows reliable shape memory behavior, allowing repeated shape recovery under appropriate thermal stimuli. Its outstanding reprocessability and degradability facilitate the recovery of both the resin matrix and valuable metals from decommissioned devices, offering a sustainable end-of-life strategy. This multifunctional epoxy system provides a promising pathway for the development of environmentally friendly, high-performance insulating materials for power equipment and electronic applications.