Enhanced thermal conductivity for polyimide composites with a three-dimensional silicon carbide nanowire@graphene sheets filler

Abstract

A rigid three-dimensional structure composed of silicon carbide (SiC) nanowire@graphene sheets (3DSG) was prepared using a high frequency heating process. The polyamide acid was then infused into the three-dimensional structure and imidized at 350 °C. The thermal conductivity of polyimide (PI)/3DSG composites with 11 wt% filler addition can be up to 2.63 W m⁻¹ K⁻¹, approximately a 10-fold enhancement when compared with the results obtained using neat PI. Furthermore, the 3DSG shows a better synergistic effect in thermal conductivity improvement, relative to a simple mixture of SiC nanowires and graphene sheets (GSs) fillers with the same additive content. The reinforced thermal properties can be attributed to the formation of efficient heat conduction pathways among GSs.