Efficient preparation of BN/UHMWPE composites with oriented thermal conductivity by powder solid-state extrusion

With the advent of the 5G era, integrated and miniaturized intelligent equipment put forward more demands and higher requirements for thermal management materials. In this study, the eccentric rotor solid extruder was applied to fabricate BN/UHMWPE oriented composites with high thermal conductivity by establishing the oriented segregated 3D thermal conductive network at 125 °C, below the melting temperature of the UHMWPE matrix. The as-prepared composite exhibited high orientation (orientation factor 0.826), high thermal conductivity (6.25 W⋅m−1K−1), outstanding electrical insulation and thermal stability, as well as excellent cost-effectiveness at 29.2 vol% BN loading, making it attractive for electronic packaging applications. In addition, we proposed a honeycomb thermal conductive model which can precisely calculate the theoretical thermal conductivity of oriented segregated composites. This research provided a prospective and reliable strategy to prepare polymer-based thermal interface materials (TIMs) with high thermal conductivity by constructing oriented 3D thermal conductive networks via powder solid-state extrusion.