Monitoring the Mechanical and Electrical Degradation Behaviors of Epoxy Resin-Based Colloids under Extreme Conditions

Epoxy resin and amine curing agents containing CaCO3 (epoxy resin AB colloids) have been widely utilized in electronic device manufacturing and other engineering fields, owing to their high glass transition temperature (Tg), exceptional mechanical strength, and excellent dielectric properties, serving as a key molding and sealing agent. However, over time and under the influence of the environment, epoxy resin will undergo aging, leading to a decline in its performance and a shortened lifespan. The focus of this work is on the aging processes and mechanisms of epoxy AB colloids from the perspective of mechanics and electricity under extreme conditions. The degradation behavior and deterioration mechanisms of the structural, mechanical, and electrical properties of epoxy resin AB colloids at aging temperatures are discussed in depth. It shows that the glass transition temperature of the resin increases after low-temperature aging, while it decreases after high-temperature aging. At the same time, after high-temperature aging, the C–OH bonds inside the resin break, and chemical water absorption occurs, with the water absorption rate following Fick’s second law. Surface peeling and holes also appear, while the resin after low-temperature aging does not absorb water or break chemical bonds, only reducing the free volume. Taking all these factors into account, the resistivity, contact angle, and mechanical properties of the resin are degraded, especially samples after high-temperature aging, degrading more severely. Furthermore, after high-temperature aging, the dielectric constant and dielectric loss of the resin increase while the internal dipole chain segments are more easily polarized, making it easier to store and release charges, whereas the changes in resin after low-temperature aging are the opposite.