Synergistic enhancement mechanism study of mechanical and thermal conductivity of GNP/SCF modified PEEK composites

The improvement of thermal conductivity of thermoplastic composites is more dependent on the addition of thermally conductive fillers, and too much of fillers can lead to a significant decrease in mechanical properties. In order to reduce the negative correlation between thermal conductivity and mechanical properties of thermoplastic composites, in this study, graphene (GNP)/short-cut carbon fiber (SCF) synergistically reinforced network structure was constructed, high strength thermal conductivity PEEK based composites were prepared using injection molding technology. The effects of GNP/SCF synergistically reinforced network structure on the thermal conductivity, mechanical properties of PEEK composites were studied. The results showed that when the mixed filler ratio was 25 wt.% (5 wt.% GNP and 20 wt.% SCF), compared to the pure PEEK, the thermal conductivity was improved by 356.2%, tensile strength by 43.29%, the heat dissipation rate by 16.2 °C/min. The above experimental results indicate that the GNP/SCF synergistically reinforced network structure can significantly improve the thermal conductivity of composites while maintaining high tensile strength.