Polyurethane composites with enhanced thermal conductivity containing boron nitrides

Boron nitride (BN) is very promising particulate fillers for production of polyurethane (PUR) composites dedicated to thermally conductive materials in electronic devices. Composites containing polyurethane-based matrices filled with BN were prepared. The effect of the filler content on the mechanical (the compressive strength), physical (process parameters, the density) and thermal properties (thermal conductivity) of the final composite material were determined. Foams obtained were characterized in terms of their process parameters such as: cream time, gel time and tack-free time. The mechanical properties of the composites were improved (compressive strength increased about 40% reached at very low filler content 3 wt % of BN), and the relative increase of thermal conductivity, as compared to the matrix, was about 8%. It was concluded that BN can be used as a filler to obtain rigid PUR foams having the characteristics of thermal conductive material.