Study on Aging Mechanism of Bisphenol A Epoxy Resin Based on Molecular Simulation

Abstract

In order to study and analyze the aging mechanism of epoxy resin, the aging characteristics of epoxy resin were studied by molecular dynamics. Firstly, the curing and crosslinking of bisphenol A epoxy resin with tetrahydrophthalic anhydride (THPA) with good electrical properties was carried out. Then, the aging process of epoxy resin molecular chain was studied by molecular dynamics simulation, and it was verified by infrared spectrum and the bond length distribution of molecular chains. The results show that chemical bond breaking occurs in the aging process of epoxy resin, and small molecular segments are produced, resulting in the decline of mechanical properties of epoxy resin. The epoxy resin will produce H2O, free hydroxyl groups and free hydrogens in the aging process. Free hydroxyl groups and free hydrogens can recombine to form H2O, and H2O will lead to a decline in insulation properties of the epoxy resin. The infrared spectrum curves of epoxy resin in aging and non-aging models show that the benzene rings in epoxy resin are stable, and the positions of breaking chemical bonds are mainly concentrated on ether bonds. The bond length distribution curves of epoxy resin in aging and non-aging models show that the peak values of carbon-oxygen bonds and carbon-hydrogen bonds are obviously different, and it indirectly verifies the breaking and formation of chemical bonds in the aging process of epoxy resin.