With the continuous increase of power levels, power equipment put forward higher requirements on the heat resistance of insulating materials such as basin-type insulator. However, it is sometimes difficult to take into account the heat resistance requirements of single-component curing agent when it meets the mechanical and breakdown properties of insulating materials. In order to explore the effect of the method of curing agent compounding on the heat resistance of epoxy resin curing products, this paper mixed hexahydrophthalic anhydride (HHPA) and tetrahydrophthalic anhydride (THPA) to obtain the epoxy resin formula system under different curing agent ratios and tested its heat resistance. In this paper, the compound of HHPA and THPA was used as a new curing agent, and are cured with EP at high temperature. The heat resistance of EP curing compound was tested by Differential Scanning Calorimeter (DSC), Dynamic Mechanical Analyzer (DMA) and Thermos Gravimetric Analyzer (TGA), and the mechanism of the influence of the compound curing agent on the heat resistance of the EP cured compound was analyzed. After compounding the curing agent, the glass transition temperature of the EP compound has been increased to a certain extent by the DSC method, which is up to 10.51% higher than that before the compound is not compounded; the DMA method also has a similar conclusion. However, the thermal decomposition temperature of the EP compound under the compound curing agent has dropped significantly. The compounding of HHPA and THPA can increase the glass transition temperature of the EP cured product, but also reduce the thermal decomposition temperature of the EP cured product. The increase in the glass transition temperature is because the two different six-membered rings in the side groups reduce the flexibility of the molecular chain, and the decrease in the thermal decomposition temperature is related to the -C=C- bond in THPA, which will be further stimulates the scission of the molecular chain after thermal decomposition, resulting in the decrease in the thermal decomposition temperature of the EP cured product.
 

Epoxy resin,hexahydrophthalic anhydride,tetrahydrophthalic anhydride,glass transition temperature,thermogravimetric analysis