Highly thermally conductive and insulating aramid/polyphenylene sulfide composite paper with gradient and sandwich structures

With rapid industrial development, effective thermal management has become essential for modern insulating materials. However, conventional aramid paper-based materials face substantial challenges in meeting these evolving demands due to their low thermal conductivity. This study demonstrates a novel fabrication method combining natural sedimentation filtration and thermal lamination to integrate hexagonal boron nitride (h-BN) into aramid/polyphenylene sulfide (PPS) composite paper, resulting in high thermal conductivity insulating aramid composite paper with a gradient structure and sandwich structure. At 60 wt% h-BN loading, the composite exhibits remarkable through-plane thermal conductivity (0.461 W/mK) and breakdown strength (40.96 kV/mm). These values show 255% and 31.8% improvements, respectively, over the h-BN-free control sample prepared under identical conditions. The thermal conductivity network formed by h-BN significantly enhances the TC of the composite. The exterior PPS film layer of the sandwich structure substantially augments the composite paper's resilience against thermal stress, chemical corrosion, and electromagnetic radiation. This enhanced durability renders the material highly promising for applications in various domains, including but not limited to electronics and electrical engineering.