Dielectric films with good dielectric breakdown strength based on poly(arylene ether nitrile) enhanced by nano boron nitride and graphene oxide via noncovalent interaction

Abstract

In recent years, boron nitride and graphene have been widely used in various industries due to their special properties. It is known that the introduction of GO into matrix resin can achieve high dielectric constant and low breakdown strength. In this work, a filler of h-BN-GO was designed through a simple one-step ultrasonic blending method without any surface modification, which is based on the π-π interaction between graphene and boron nitride because of their similar layered structure. Then, a flexible dielectric film with good dielectric breakdown strength and thermal conductivity was obtained through introducing the h-BN-GO fillers into poly(arylene ether nitrile). The various testing results show that the nanocomposites possess high mechanical properties (tensile strength > 99 MPa) and thermal stability (T5% > 453 °C). Notably, as the h-BN-GO content increases from 0 wt% to 7.5 wt%, the dielectric constant increases from 4.2 to 7.4 at 1 kHz. Most importantly, when the filler content is 7.5 wt%, the breakdown strength of the h-BN-GO/PEN film is 91.6% higher than that of the GO/PEN film with the same load. Therefore, these h-BN-GO/PEN nanocomposite films exhibit potential in applications as flexible dielectric films.