▎ 摘　　要

A novel poly(m-phenyleneisophthalamide) (PMIA) dielectric nanocomposite was successfully fabricated with functionally reduced graphene oxide (frGO) and multi-walled carbon nanotubes (MWCNTs) hybrid fillers. Due to effective functionalization of reduced graphene oxide as well as pi-pi interaction between frGO and MWCNTs, FGC (FGC) hybrid fillers were well-distributed in PMIA matrix. The relevant properties of FGC/PMIA dielectric nanocomposite were researched, and results demonstrated that the dielectric constant of PMIA nanocomposite with 3 wt% FGC hybrid fillers was increased to 12.8 (increased by 290%). Due to the existence of FGC fillers, the THeat-resistance index of FGC/PMIA nanocomposites displayed an obvious increment. In addition, the "bridge effect" of MWCNTs on improving thermal conductivity of FGC/PMIA dielectric nanocomposite was also significant. For PMIA nanocomposite with 3 wt% FGC hybrid fillers, the thermal conductivity was remarkably increased to 7.38 W/m center dot K of in-plane direction and 0.81 W/m center dot K of through-plane direction. Consequently, these results reveal a new approach for preparing FGC/PMIA dielectric nanocomposite with high operating temperature and outstanding thermal conductivity, which can meet the urgent demand for high-temperature applications.