Fabrication of High Thermally Conductive and Electrical Insulating Composites by Boron Nitride-Nanosheet-Coated PEEK Fiber

The development of polyether ether ketone (PEEK)-based thermally conductive insulating composites is required in miniaturized electronic devices with a high power density where heat needs to be evacuated. However, the low thermal conductivity (TC) remains a great challenge, significantly restricting the large-scale applications of PEEK. Here, a novel class of boron nitride nanosheets (BNNSs)/PEEK composites with excellent heat dissipation properties through BNNS-coated PEEK fiber is developed, through simple hot-press sintering. A direct comparison of experimental measurements between the BNNSs/PEEK fiber composites and the BNNSs/PEEK powder composites indicates that the TC is greatly improved in the presence of the well-orientated structure of BNNSs. In addition, the composite with high loading of BNNSs exhibits a combination of high tensile strength and significant electrical insulation (volume electrical resistivity beyond 10 9 Ω cm). The experimental data demonstrate that it has broad and bright prospects for application in a range of emerging electronic devices, which also provide great potential for enhancing the thermal management application of PEEK-based composites.