Reactive molecular dynamics simulation on the pyrolysis characteristics of epoxy resin under the effect of partial discharge active products

Abstract

Aromatic amine cured Bisphenol F epoxy resin is used as a pivotal solid insulation material in electrical equipment at low temperature and extreme environment. Partial discharge (PD) can lead to an increase in local temperature, which leads to pyrolysis, and the existence of PD active products will aggravate the pyrolysis process of insulating materials. In order to investigate the effect of PD active products on the pyrolysis characteristics of aromatic amine cured epoxy resin, the pyrolysis process of epoxy resin under partial discharge active products is simulated based on ReaxFF. The types and changing trend of small molecular products and the mechanism of PD active products acting on the pyrolysis process of epoxy resin are analyzed. The results show that the oxidation of hydroxyl and C-N bridge bonds by PD active products is the main reason for accelerating the pyrolysis of epoxy resin, which changes the main pyrolysis path of epoxy resin cross-linked structure. The thermal stability of cross-linked epoxy resin decreases under the action of active products, and the types and change trend of small molecular products generated in the pyrolysis process also changes greatly with the change of pyrolysis path.