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

Abstract 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.