An efficient strategy for preparation of high-k poly(arylene ether nitrile)-based dielectrics with enhanced thermo-stability and good temperature independence

In this work, the encapsulated barium titanate (BT) (C-PEN@BT) nanoparticles were successfully prepared via rotary coating technology combined with a post-treatment chemical bonding process, by using carboxyl-functionalized poly(arylene ether nitrile) (C-PEN) as modification agent. The TEM, FTIR and TGA results confirmed that the polymer layer (about 8 nm) has been uniformly surrounded on the surface of BT nanoparticles. Then, a facilitated physical dispersion technology was employed to prepare C-PEN@BT filled composite films using crystalline PEN as matrix and 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPH) as a novel cross-linking agent. The effects of both the surface modification of BT nanoparticles and matrix cross-linking on the mechanical, thermal and dielectric properties of PEN-based composites were investigated in detail. Compared with PEN-I film, the latter results showed that the strong interface interactions exerted between polymer matrix and CPEN layer on BT surface, especially the formation of cross-linking network across the PEN matrix, resulted in increased tensile strength and Young’ modulus by 29% and 32%, respectively. More importantly, the PEN/C-PEN@BT composite film shows stable dielectric properties in the temperature range of 20–204 °C, which is very close to the glass transition temperature.