Fabrication of silicon carbonitride-covered boron nitride/Nylon 6,6 composite for enhanced thermal conductivity by melt process

The surface-treated boron nitride (BN) particles are prepared with polysilazane (PSZ) by using a dip-coating method to fabricate a thermally conductive interface material. PSZ-BN particles are generated by crosslinking of PSZ on BN and heat treatment of the formed PSZ-BN at 700 °C to convert PSZ-BN to SiCNO-BN. The SiCNO-BN particles are fabricated with Nylon 6,6 by using an extruder and injection molding method. The interfacial adhesion between the BN particles and the Nylon 6,6 matrix is enhanced by surface treatment of the BN particles. The surface-treated BN/Nylon 6,6 composites exhibit thermal conductivity ranging from 0.3270 to 0.4230 W/m K (through-plane) and 1.6510 to 4.960 W/m K (in-plane), which is higher than that in the case of loading with pristine BN/Nylon 6,6 composites at the same weight fraction. The tensile strength and tensile modulus increase from 59.13 and 1.67 GPa with the use of pristine BN to 69.15 and 2.10 GPa with incorporation of SiCNO-BN into the Nylon 6,6 composite.