Preparation and properties of thermally conductive flame resistant composites based on boron nitride hybrid filler

Epoxy composites that possess high thermal conductivity and synergistic flame resistance are anticipated to achieve efficient heat dissipation and minimal fire risk in electronic equipment， thereby exhibiting promising application prospects in electronic products. In this study， SnO2 nanoparticles are modified using γ-aminopropyltriethoxysilane， and the resultant modified SnO2 （m-SnO2） is further integrated with boron nitride nanowires （BNNS） through electrostatic self-assembly to produce BNNS@m-SnO2 hybrid fillers. Subsequently， thermally conductive and flame-resistant composites with a specific orientation structure are fabricated using the blade-casting method， with epoxy resin serving as the polymer matrix. The results indicate that the Zeta potential of the modified SnO2 nanoparticles shift from -19.1 mV to 28.7 mV， enabling their combination with BNNS （Zeta potential of -27.8 mV） through electrostatic interaction. The incorporation of BNNS@m-SnO2 hybrid fillers significantly enhances the thermal conductivity and flame resistance of the epoxy composites. Notably， the thermal conductivity of the EP/BNNS@m-SnO2-10%（mass fraction） composites reach 3.79 W·m-1·K-1， while also demonstrating a higher peak combustion temperature （410.9 ℃） and a lower peak heat release rate （302.2 W·g-1）.