High thermal conductivity and flame-retardant epoxy-based composites with low filler content via hydrazine foaming of graphene oxide and boron nitride hybrid fillers

In this study, we developed a composite material for thermal conductivity by creating a hyperbolic boron nitride (BN) and graphene oxide (GO) structure with surface treatment using phosphorus-containing functional groups. The resulting composite, with a 4.04 vol % hybrid filler content, was impregnated with epoxy resin. The com-posite achieved a thermal conductivity of 0.95 W/mK and exhibited a significant thermal conductivity enhancement (TCE) when compared to the neat EP (377 %), demonstrating its potential for mitigating thermal accumulation in industrial applications. Additionally, the tensile strength of the composite significantly improved up to 45.3 MPa and had excellent flame-retardant properties. These results highlight the effectiveness of the hybrid filler approach in enhancing thermal and mechanical properties. The developed composite holds promise for various applications that require improved heat transfer and enhanced mechanical performance.