Improving dielectric properties of poly(arylene ether nitrile)-based composites films modulated via polyaniline-assisted barium titanate

The polymeric dielectric materials with flexibility, better thermal stability and high dielectric constant have drawn increasing attention due to the wide applications in electrical systems. Herein, the polymer-based dielectric composites were designed by the infiltration of polyaniline (PANI) coated barium titanate (BT) into poly(arylene ether nitrile) (PEN) matrix. It is demonstrated that the dielectric constant of composites could be as high as 15.3@1 kHz, which is approximately 4 times higher than that of pure PEN matrix ( ε r  ≈ 3.8@1 kHz). Meanwhile, the maximum dielectric loss of composites (tan δ  ≈ 0.0403@1 kHz) remains comparable to that of PEN (tan δ  ≈ 0.0147@1 kHz). This phenomenon attributes to the large charge accumulation and interfacial polarization on the interfaces between PANI, BT and PEN. The better interconnectivity caused by the π – π conjugation and hydrogen bond interactions between PANI interlayer and PEN matrix also can facilitate the polarization transmission throughout PANI coating, substantially enhancing dielectric constant. Besides, the PANI-BT/PEN composite films present better thermal stability ( T 5% > 500 °C) and flexibility. This work provides an eco-friendly and easy-handling strategy as alternative way to fabricate high-performance PEN-based dielectric composites.