Study on the Aging Behavior of Epoxy Resin and the Influence of Hydrolyzable Chlorine

To investigate the aging behavior of epoxy resin, commonly used as an insulation material in electrical equipment, and the influence of hydrolyzable chlorides, this study conducted aging experiments on epoxy resin specimens with different hydrolyzable chloride contents and temperature conditions. The changes in mass loss, flexural strength, and dielectric properties were analyzed. The results showed that the mass loss rate of the aged epoxy resin specimens ranged from 6.79% to 9.78%, the flexural strength decreased by 59.2% to 62.4%, and the dielectric properties exhibited an initial increase followed by a decrease trend, with the breakdown voltage increasing by 13.52% to 15.51%. Through density functional theory analysis, we verified the impact of hydrolyzable chlorides on the band structure of the epoxy resin system, further confirming the differences in dielectric properties. In addition, Fourier-transform infrared spectroscopy analysis revealed the phenomenon of molecular bond breakage within the aged epoxy resin. Molecular dynamics simulations using the ReaxFF force field demonstrated the fragmentation of carbon chain backbone and disruption of crosslinking structure, accompanied by the generation of free molecules such as H2O, CO2, and HCl, which influenced the various properties. In summary, this study aims to explore the aging mechanisms of epoxy resin insulation materials and the effects of hydrolyzable chloride content, providing valuable insights for the long-term stable operation of electrical equipment.