Tailored interphase and thermal interface resistance of self-assembled thermally reduced graphene oxide-polyamide hybrid/epoxy composites with enhanced thermal conductivity

Thermally reduced graphene oxide-polyamide (TrGO-PA) hybrids were fabricated by self-assembly between TrGO nanosheets and PA microparticles, and the dispersibility, interphase extension, and thermal conduction mechanism of TrGO-PA/epoxy (EP) composites were investigated. Most of the oxygen-containing functional groups of TrGO were removed, and a conjugated structure of graphene was recovered. TrGO was distributed evenly on the PA surface via electrostatic adsorption between TrGO and PA, which resulted in the inhibition of TrGO aggregation in the epoxy matrix. Compared with that of TrGO/EP and PA/EP composites, the thermal interface resistance (R-TIM) of TrGO-PA/EP composites was greatly decreased to 38.3 mm(2) kW(-1) and the thermal conductivity was improved to 0.268 W/(m K), which was attributed to the enhanced dispersibility of TrGO-PA and the enlarged interphase in TrGO-PA/EP composites. A schematic model of thermal conduction mechanisms was proposed based on the formation of contiguous thermal transfer pathways by bridged TrGO adsorbed on well-dispersed PA microparticles in TrGO-PA/EP composites. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47826.