Preparation of a Wood-Based Thermally Conductive Composite

To improve the thermal conductivity of balsa wood, infiltrating boron nitride (BN) and epoxy (EP) resin into the wood after delignification treatment was shown to be a feasible strategy. Scanning electron microscopy, energy-dispersive x-ray spectroscopy, Fourier transform infrared analysis, and x-ray diffraction analysis were used to verify the successful dispersion and immobilization of BN and EP in the wood. The effect of the ratio of BN to EP on the thermal properties was subsequently examined. The thermal conductivity of the BN/EP composite increased with higher BN content in the EP resin. For a BN-to-resin weight ratio of 1:70, the thermal conductivity reached a maximum of 0.388 W m⁻¹ K⁻¹, representing a 605% increase compared to natural balsa wood. The thermal conductivity decreased for higher ratios. Using a BN–EP ratio of 1:70, nine BN/EP composites were impregnated, superimposed, and cured together. The measured thermal conductivity was 0.473 W m⁻¹ K⁻¹. The performance of the BN/EP composites as a light-emitting diode (LED) heat dissipation substrate was evaluated using numerical simulation and infrared imaging. The sample exhibited excellent thermal conductivity performance, providing a potential avenue for preparing LED heat dissipation substrates.