Improved thermal conductivity of poly(dimethylsiloxane) composites filled with well-aligned hybrid filler network of boron nitride and graphene oxide

Abstract

Polymer composites have attracted considerable attention due to their easy processability, low cost, and various applications. However, intrinsic poor thermal, electrical properties of polymer always have been the bottlenecks of multifunctional technical development. In this study, fabrication of low dielectric loss and highly thermal conductive composites was investigated through hybridization of silane-treated reduced graphene oxide (rGO) and boron nitride (BN), sintering of silver nanoparticles (AgNPs) on the surface of two-dimensional fillers, and infiltration of poly(dimethylsiloxane) (PDMS). The well-ordered filler structure was achieved by aligned BN on the rGO surface. The aligned PDMS/BNA-SrGOA composites, which form heat transfer paths along the filler orientation of two-dimensional BN and GO, exhibited high thermal conductivities of 10.91 and 1.27 W/mK according to in-plane and through-plane direction in a 1:2 ratio of BN and rGO. In addition, the dielectric loss was decreased by interaction with BN compared to that with only the rGO composites. Finally, the treatment of a silane coupling agent on the rGO surface reduced the interface resistivity between the filler and matrix, which reinforced the thermal, electrical, mechanical properties. © 2021 The Authors