Preparation of a 3D BN network structure by a salt‐template‐assisted method filled with epoxy resin to obtain high thermal conductivity nanocomposites

Abstract It is crucial to improve the thermal management capability of polymeric materials while maintaining their electrical insulating properties. Constructing thermally conductive networks with three‐dimensional structures inside polymers is an efficient way to build thermally conductive pathways. A unique three‐dimensional interconnected hexagonal boron nitride (h‐BN) skeleton was prepared by sacrificing salt templates. The prepared three‐dimensional skeleton exhibited a sponge‐like structure. BN served as the main body of the thermally conductive skeleton, and polyvinylidene fluoride (PVDF) served as the binder between BN. It was subsequently supplemented with vacuum impregnation of epoxy resin to improve the thermal conductivity of the epoxy composites. The composite achieved a thermal conductivity of 1.245 W/(m·K) at a filler loading of 21 wt%, and equivalent to a thermal conductivity enhancement of 611.4% compared to the pure resin matrix. The prepared composites exhibit good thermal management capabilities and excellent insulation properties, showing great potential for electrical and electronic device applications. This work provides a new direction for the preparation of thermal management materials.