Bioinspired honeycomb structure enables high thermal conductivity in h-BN/PSAE composites via TBA-templating

Efficient thermal management is a critical challenge for next-generation electronics, where conventional polymer-based materials suffer from inherently low thermal conductivity. Inspired by natural honeycomb structures, we developed a freeze-casting strategy to fabricate high-performance hexagonal boron nitride (h-BN)/polysilylaryl-enyne (PSAE) composites exhibiting enhanced thermal conductivity. By leveraging the unidirectional crystallization of tert-butyl alcohol (TBA), a highly ordered h-BN honeycomb scaffold was constructed, facilitating the formation of efficient phonon conduction pathways. The composites, with a low h-BN (10 μm) ratio of 23 vol%, exhibit an outstanding omni-directional thermal conductivity of 4.71 W/(m·K) along the z-axis and 3.44 W/(m·K) along the x-axis, significantly outperforming conventional polymer composites. Moreover, dielectric characterization confirms that the honeycomb structure enhances anisotropic dielectric behavior ( ε rz  = 3.68, ε rx  = 3.32, for h-BN (10 μm) at 23 vol%). The proposed bioinspired approach presents a scalable and effective route for developing lightweight, thermally conductive composites for advanced electronic applications.