Synergistic effect of functionalized graphene/boron nitride on the thermal conductivity of polystyrene composites

Polymeric composites with enhanced thermal conductivity (TC) have great applications in thermal management materials. Herein, we reported a synergistic effect of functionalized graphene (GR) and boron nitride (BN) on the thermal conductivity (TC) of polymeric composites. Here, functionalized GR and BN were prepared by modified Hummers' method and liquid exfoliation method, respectively. The polystyrene (PS) composites were obtained via solution blending followed by hot-pressing method. The results demonstrated that the TC of the PS composites increased with the synergistic effect of functionalized GR and BN. When the mass ratio of graphene oxide/hydroxylated boron nitride (GO/BN-OH) was 7:3, the TC of the composites reached maximum and exhibited the highest TC enhancement up to 20%, but less than synergistic improvement of the TC of GR/BN with same filler loading and the TC enhancement about 21.5%. The study indicated that the oxygen-containing groups on the two dimensional thermal conducting fillers were not conducive to the increase of heat conduction.