Crosslinked poly (aryl ether ketone)/boron nitride nanocomposites containing a stable chemical bonding structure as high temperature dielectrics

Abstract

Polymer materials have been a popular choice for dielectric capacitors for decades, but their application suffers a great limitation due to their poor heat resistance. Herein, a crosslinkable poly (aryl ether ketone) (DPAEK) is synthesized as the matrix, while boron nitride (BN) nanosheets are functionalized with reactive groups, thus obtaining a kind of crosslinked poly (aryl ether ketone)/boron nitride nanocomposites as well as forming a stable chemical bonding structure at interfaces via Diels-Alder reaction. Owing to the strengthened interfaces, the nanocomposites exhibit high breakdown strength (536 MV m−1, at room temperature) and may maintain excellent dielectric stability at high temperature. In addition, the nanocomposites yield a significantly improved discharged energy density (3.83 J cm−3) and high charge-discharge efficiency (90.6%) at 500 MV m−1 and 150 °C. This work demonstrates that constructing crosslinked nanocomposites may be a viable way to fabricate high temperature dielectrics.