Study on the properties of polyamidoacid-modified high thermal conductivity epoxy resin composites

In order to cope with the demand of new energy vehicle drive motors for high thermal conductivity and high insulation potting compounds, in this paper, polyamidoacetic acid (PAA) containing hexafluoroisopropyl and sulfone groups was introduced into the epoxy resin (EP) matrix through molecular structure design. And the epoxy resin composites (PAA-B3A5/AF) with different PAA contents were prepared by compounding and filling with 30wt% of hexagonal boron nitride (h-BN) and alumina (AO) accounting for 50wt% of the content of h-BN. The effects of PAA content on the microstructure and thermal-electrical-mechanical properties of EP composites were systematically investigated. The results show that after the introduction of PAA, the epoxy resin composite has excellent thermal conductivity, and significantly enhances the insulation performance and mechanical properties. When the content of PAA was 4wt%, the thermal conductivity of the composites was 1.79 W/(m·K) at room temperature, the DC breakdown field strength was 217.5 kV·mm⁻¹, and the tensile strength was 28.92 MPa, which provided a reliable preparation scheme for obtaining epoxy potting adhesives with excellent comprehensive properties.