Preparation and Properties Study of Itaconic Acid-based Degradable Epoxy Resin Based on Dynamic Covalent Bonds

The most widely used bisphenol A-type epoxy resin (DGEBA) in electrical engineering demonstrates excellent mechanical and electrical properties. However, the insoluble and infusible characteristics of cured DGEBA make it difficult to efficiently degrade and recycle decommissioned electrical equipment. In this study, a degradable itaconic acid-based epoxy resin incorporating dynamic covalent bonds was prepared through the integration of ester bonds and disulfide bonds, with itaconic acid as the precursor. The covalent bonding effects on the mechanical, thermal, electrical, and degradation characteristics were systematically evaluated. The experimental results revealed that the introduction of dynamic ester bonds enhanced the mechanical properties and thermal stability of the resin system, achieving a flexural strength of 141.57 MPa and an initial decomposition temperature T 5% of up to 344.9 °C. The resin system containing dynamic disulfide bonds exhibited a dielectric breakdown strength of 41.11 kV/mm. Simultaneously, the incorporation of disulfide bonds endowed the epoxy resin with remarkable degradability, enabling complete dissolution within 1.5 h at 90 °C in a mixed solution of dithiothreitol (DTT) and N -methylpyrrolidone (NMP). This research provides a valuable reference for the application of itaconic acid-based vitrimer with dynamic covalent bonds in electrical materials, contributing to the development and utilization of environmentally friendly electrical equipment.