Preparation and thermal conductivity properties of high-temperature resistance polyimide composite films based on silver nanowires-decorated multi-walled carbon nanotubes

Polyimide composites have high thermal conductivity and maintain their processability and temperature resistance under low filler loading, which are essential conditions as high-power microelectronic packaging materials. We have prepared thermally conductive and high-temperature resistant copolyimide composite films by in situ polymerization. The multi-walled carbon nanotube-reinforced phase decorated by silver nanowires was homogeneously dispersed in polyamide acid solution during the in situ polymerization process due to the good dispersion of AgNWs-decorated MWCNTs filler in the matrix and the bridging action of AgNWs, thus, forming thermal transfer networks in the composites. Consequently, thermal conductivity of 0.4426 W/m·K was achieved with only 3.0 wt% addition, while the glass transition temperature (T g ) and heat-resistance index (T HR ) were increased to 295.65 °C and 297.88 °C. This method is simple, efficient, and environmentally friendly, and it can achieve simultaneously the formation of AgNWs and inter-decorated carbon nanotubes, which eventually realized well-dispersed matrix and prepared thermally conductive composites.