Expanding the Process Window of Epoxy Composite Insulating Materials by Compounding Anhydride

Phthalic anhydride (PA) / epoxy resin (EP) cured compound has good electrical and mechanical properties. However, PA has a very high melting point, which will lead to narrow temperature window and poor curing process of epoxy resin composites. In order to improve the temperature and process window of PA/EP composites, the heat flow curve and melting point of the compound curing agent were measured by using the mixture of Me-HHPA and PA, and the gel time of the compound curing agent was tested to explore the effect of the compound curing agent on the curing window. The experimental results show that the curing exothermic rate decreases with the increase of Me-HHPA content; when the ratio of Me-HHPA to PA is 5: 1, the melting point of the compound curing agent is 17°C, and the curing time of the compound curing agent with epoxy resin is longer, which is 43.1% and 10.67% higher than that of using PA or Me-HHPA as curing agent alone.