Preparation and performance of PEN-OH@BNNS-OH/PEN interlayer dielectric films with superior interfacial compatibility

Polymer dielectric composites featuring great thermal stability, excellent mechanicals, and good dielectric properties have sparked considerable attention. Here, the preparation of hybrid filler was first performed. The hydroxyl end-capped polyarylene ether nitrile (PEN-OH) was synthesized and then hydroxy BNNS (BNNS-OH) was combined with PEN-OH to obtain PEN-OH@BNNS-OH, which is fabricated by ultrasonic combined with applying post-solid phase chemical reaction technology. The aim is to use the -OH interactions of BNNS-OH and PEN-OH to form hydrogen bonds that greatly enhance interfacial heat transport. Next, the post-solid phase chemical reaction is utilized to make PEN-OH crystallize, and its crystals located on the two-dimensional planes of BNNS-OH or between the layers can serve as a thermal bridge. Then, the as-prepared film with 10 wt% hybrid filler displays high thermal conductivity (1.17 W/m.K), 13.67%-fold higher than pure PEN film, boasts outstanding mechanical properties (stress 105 MPa, strain 6%), high glass transition temperature (Tg: 224 ℃), a dielectric constant (4.30 at 106 Hz), together with low dielectric loss (0.007 at 106 Hz). Besides, the film was post-treated to increase the thermal conductivity to 1.77 W/m.K, reach a higher Tg of 263 ℃, reduce the dielectric constant and loss to 3.68 and 0.006 at 106 Hz. Thus, it is suitable as a high-temperature-resistant dielectric material.