Study on Thermal Stability and Space Charge Characteristics of Epoxy/PMIA Fiber Composites

Aramid fiber insulation poles are widely used because of their excellent mechanical and electrical properties, and the type of curing agent plays an important role in the performance of insulation poles. In the work, the effects of different curing agents (tetrahydrophthalic anhydride (THPA), methyltetrahydrophthalic anhydride (MHAC) and methylnadic anhydride (MNA)) on the thermal stability and space charge characteristics of epoxy resin/PMIA composite structures were investigated based on molecular simulation calculations and experimental methods. Compared with other curing agent/epoxy systems, MHAC/epoxy (EPMH) systems has lower coefficient of thermal expansion, and it has stronger binding ability to PMIA. Under the action of the electric field, the energy gap between the highest electron-occupied orbital and the lowest empty orbital of the EPMH system is larger. The EPMH/PMIA composite system has less space charge accumulation under the electric field, and the charge dissipation rate of the material is faster when the electric field is removed.