Novel Poly(m‐phenyleneisophthalamide) Dielectric Composites with Enhanced Thermal Conductivity and Breakdown Strength Utilizing Functionalized Boron Nitride Nanosheets

Dielectric polymer‐based composites with high breakdown strengths and thermal conductivities have attracted considerable attention when applied in electronic devices. In this study, a novel poly(m‐phenyleneisophthalamide) (PMIA) dielectric nanocomposite is successfully fabricated by introducing functionalized hexagonal boron nitride nanosheet (fBNNS) fillers. Due to effective functionalization of hexagonal boron nitride nanosheets (BNNSs), fBNNSs fillers are homogeneously dispersed in the PMIA matrix. The breakdown strength and thermal conductivity of PMIA/fBNNSs dielectric nanocomposite are investigated. Research results indicate that the breakdown strength of fBNNSs‐12 reaches 105.6 MV m −1 , which is 1.34 times that of pure PMIA. Moreover, owing to high thermal conductivity of fBNNSs, the thermal conductivities of fBNNSs‐12 are observably increased to 8.06 W m −1 K of in‐plane direction and 0.84 W m −1 K of through‐plane direction, respectively. Considering these properties, the manufactured PMIA/fBNNSs dielectric nanocomposites show potential applications in field of electronics.