High-oriented two-dimensional BN reinforced composites with high thermal conductivity via simple vertical method

As electronic devices become more compact, efficient thermal management is crucial for their performance and reliability. In this study, hexagonal boron nitride (BN) was modified with 3-aminopropyltriethoxysilane (KH550) to obtain surface functionalized K-BN (KH550-modified BN), which was incorporated into high-impact polystyrene (HIPS) to create HIPS/K-BN composites containing both vertically aligned and randomly distributed fillers. Using a twin-screw extrusion process, we produced HIPS/K-BN pellets with varying degrees of K-BN alignment and hot-pressed them to fabricate composites with high orientation. The composites with vertically aligned K-BN exhibited superior thermal conductivity, with the 40 vol% K-BN filled composite reaching 4.46 W/(m·K). Additionally, the composites demonstrated good thermal stability and reliable dielectric properties (ε ⊥  = 2.94, tanδ = 3.14 × 10 −4 ). This approach offers a cost-effective method for producing polymer composites with enhanced thermal performance, which could be beneficial for thermal management in high-power electronics.