Unprecedentedly high thermal conductivity of carbon/epoxy composites derived from parameter optimization studies

Abstract

Efficient removal of heat accumulation from electronic devices has been considered an important issue because it is prone to induce reduced lifetime, heat shock, ignition, and malfunction during their operation. To that end, optimized epoxy composites, which are fabricated by dispersing a mesogen-containing polymer compatibilizer (BPIB)-applied multi-layered graphene nanoplate (MGNP) filler into a mesogen-containing epoxy (DGEBP) matrix (BPIB-MGNP/epoxy), are designed toward high thermal conductivity at the low filler loading content. Various effects on its thermal conductivity, including size, thickness, and dispersion of fillers along with the crystalline property of epoxy, are systematically investigated by comparing with their intermediate counterpart materials. The extended micromechanics model, which was modified using a power law from its initial one, was employed to address the filler size effects on its thermal conductivity as well as an exponential increase of thermal conductivity with increasing filler loading content. Thickness effects of carbon fillers are examined by comparing GNP/epoxy composites with single-layered graphene filler-based epoxy composites. The effects of dispersion properties of the fillers in the epoxy composites are also investigated using the theory prediction plot based on the extended micromechanics model. The comparison between experimental and theoretical prediction led us to study crystalline properties of the BPIB-MGNP/epoxy composites because it was unexpected and beyond the theoretical traces. An Ashby plot is prepared to evaluate the state of our results by comparing them with the reported state-of-the-art composite performances.