Bioinspired modification strategy to improve thermal conductivity and dielectric constant of natural rubber composite for thermal management applications

Natural rubber (NR) composites filled with modified aluminum nitride (AlN) particles were successfully fabricated with high thermal conductivity and dielectric constant. To boost the interfacial interactions form thermal conductive networks between AlN and NR matrix, a mussel-inspired polydopamine and γ-(2,3-epoxypropoxy)propy trimethoxysilane (KH560) grafting were combined to yield AlN-PDA-KH560. The double-layer structure led to good filler dispersion of AlN-PDA-KH560 with decreased interfacial thermal resistances. As a result, the largest thermal conductivity in 30 phr AlN-PDA-KH560/NR was reached to 0.48 W/m K, which was 2.28 times larger than pure NR. Furthermore, the 30 phr AlN-PDA-KH560/NR composite also had relatively high dielectric constant (3.95 at 10 3 Hz) and low dielectric loss (~0.01 at 10 3 Hz), benefiting for long time operation and thermal diffusion. This strategy provides a facile, low-cost, and scalable method to fabricate high electrical and thermal conducting composites for strong potential in thermal management for electronic devices.