Thermal conductive nylon 6 composites using hybrid fillers to construct a three‐dimensional thermal conductive network

The rapid progress in miniaturization and integration of semiconductor power devices has made heat dissipation a critical concern in the development of high‐performance semiconductor devices, thereby increasing the demands for the heat transfer efficiency of polymer composites. To address this issue, an efficient three‐dimensional (3D) heat conduction network structure is constructed in the polymer matrix by leveraging the mutual reaction of amino and epoxy groups on the surface of the filler treated by coupling during the melt mixing process, this approach leads to an enhancement in the thermal conductivity of the composites. First, the inert surfaces of graphene nanosheets (EX‐G) and carbon fibers (CF) are coated with polydopamine (PDA) to form active sites. Subsequently, the graphene (EX‐G), alumina (Al2O3), and carbon fiber (CF) are treated with an amine coupling agent (KH550) and epoxy coupling agent (KH560), respectively. Notably, at a filler content of 25 wt%, the thermal conductivity (TC) of the composites increases by approximately 282% compared to pure nylon 6. This research contributes novel insights into the field of thermally conductive polymer composites. Highlights The surface of the EX‐G and CF covered by PDA generates active sites. Fillers reduce the interface thermal resistance through chemical bonds. Fillers surface reaction builds a 3D thermal conductive network. 3D network structure can significantly improve the TC of composites. Only 25 wt% of hybrid fillers in a 282% increased TC of composites. Schematic illustration of heat flow conduction through a 3D thermally conductive structure in a composites.