Enhanced dielectric performances of strontium barium titanate nanorod composites via improved interfacial compatibility.

High performance film capacitor has attracted widespread attention due to their increasing applications in electronic devices. However, the insufficient dielectric properties of dielectrics in capacitors severely restrict their practical application. In this work, the dielectric performances of polyarylene ether nitrile (PEN) are effectively enhanced by the synthesizing and employing of carboxylated PEN (CPEN) modified one-dimensional (1D) strontium barium titanate nanorod (BSTNR) (CPEN@BSTNR), as well as applying of hot stretching technique. CPEN@BSTNR is prepared via the synthesizing of BSTNR, modifying with γ-Aminopropyl triethoxysilane (KH550), and grafting by CPEN. Deriving from the 1D structure of BSTNR and the peripheral modification by CPEN, compatibility of CPEN@BSTNR in PEN has been significantly improved. Moreover, CPEN@BSTNR orients in the polymer matrix attributing to the hot stretching. Consequently, the hot stretched 16 wt% CPEN@BSTNR/PEN film exhibits an increased dielectric constant of 17.30 and maintained a breakdown strength of 204.1 kV/mm. As a result, this stretched composite film demonstrates an energy density up to 3.19 J/cm, with a 300 % improvement over pure PEN. This enhanced dielectric properties of PEN presents a promising avenue for the fabrication of high performance film capacitors.