Polyarylene Ether Nitrile/Modified Hollow Silica Composite Films for Ultralow Dielectric Properties and Enhanced Thermal Resistance

Highly heat-resistant and low-dielectric materials are crucial for achieving high-frequency communication, high-density integration, and high-temperature stability in modern electronics. In this work, surface modification of hollow silica microspheres (HGMs) using a silane coupling agent ((3-aminopropyl)triethoxysilane, KH550) yielded KHGM particles with a coating content of approximately 9.3 wt%, which were subsequently incorporated into high-performance polyarylene ether nitrile (PEN) polymers to fabricate composite films. The modified nanoparticles demonstrated significantly enhanced compatibility with the polymer matrix, while their hollow structure effectively reduced the dielectric constant of the composite film. When loaded with 50 wt% KHGM particles, the PEN-based composite film exhibited an elevated glass transition temperature of 198 °C and achieved a dielectric constant as low as 2.32 at 1 MHz frequency, coupled with dielectric loss below 0.016; compared with pure PEN, the dielectric constant of PEN/KHGM-50% decreased by 26.47%. Additionally, the composite demonstrated excellent water repellency. These advancements provide high-performance material support for applications in electronic communications, aerospace, and related fields.