Preparation of Self-Healing Imine-Disulfide Epoxy Resin for Electrical Insulation and Electronic Packaging Applications
摘要
Reliable epoxy-based insulation materials are important for electronic packaging applications in which localized mechanical damage may deteriorate electrical insulation and shorten service life. In this work, an imine-disulfide-containing curing agent was synthesized and used to construct a dynamic covalent epoxy network with self-healing capability. Fourier-transform infrared spectroscopy confirmed the formation of C=N bonds and the retention of S–S bonds in the curing component. The cured EP-IDSE network exhibited acid-triggered degradation in HCl/tetrahydrofuran (THF) solution at a pH of 2, indicating the presence of acid-labile imine linkages in the network. After controlled scratch damage and thermal healing treatment, the characteristic breakdown strength recovered from 38.5 kV mm−1 to 45.2 kV mm−1, corresponding to 92.2% of the pristine value. The leakage current, which increased after scratching, decreased again after healing and approached the pristine level. Morphological observations further showed that the scratched surface became less pronounced after thermal treatment at 60°C for 2 h, indicating thermally activated interfacial reconstruction of the dynamic network. These results demonstrate that the coordinated introduction of imine and disulfide bonds provides a feasible strategy for developing self-healing epoxy insulation materials with recoverable electrical performance for electronic packaging applications.