Largely enhanced thermal conductive, dielectric, mechanical and anti-dripping performance in polycarbonate/boron nitride composites with graphene nanoplatelet and carbon nanotube

Highly thermal conductive polymer composites synchronously with excellent dielectric and mechanical properties are highly desired in electronic devices. In this work, largely enhanced thermal conductivity (TC), dielectric constant and mechanical property were synchronously realized in polycarbonate (PC) matrix via incorporating boron nitride (BN) together with few graphene nanoplatelets (GnPs) and carbon nanotubes (CNTs). Significantly reduced interfacial thermal resistance between BN and matrix in PC/BN@GnP@CNT composites was the main reason contributed to the largely enhanced TC. By synchronously adding 20 wt% BN (BN-20), 1 wt% GnPs and 1 wt% CNTs, the TC of PC/BN-20@GnP@CNT composites reached up to 1.42 W/mK, enhanced by 647% and 103% compared with that of neat PC and PC/BN-20 composites, respectively. The dielectric constant of PC/BN-20@GnP@CNT reached up to 177 at 100 Hz (enhanced by ~50-fold compared with PC/BN-20) while the dielectric loss was kept at a low level. Compared with PC/BN-20, the yield strength, elongation at break, fracture toughness and notched impact strength of PC/BN-20@GnP@CNT were enhanced by 42%, 103%, 146% and 8%, respectively. Meanwhile, PC/BN/GnP@CNT composites showed significantly reduced ignitability and remarkable anti-dripping performance. This work promotes an effective, feasible strategy for fabricating dielectric thermal conductive polymer composites with excellent mechanical and anti-dripping performance.