Abstract: Thermally conductive and electrically insulative poly(decamethylene terephthalamide)(PA10T) composites were prepared using an instantagglomerated boron nitride (BN) powder and a microspheric magnesia (MgO) powder as fillers. A few amount of chopped glass fiber was loaded to improve the strength. Keeping the total filler loading of chopped glass fiber and fillers at 10 wt % and 60 wt % respectively, the effect of the weight ratio of BN to MgO on the thermally conductive and mechanical properties as well as flow abilities of the composites was studied. It was observed that the two thermally conductive fillers had an enormously synergistic effect on the thermal conductivity when the weight ratio of BN to MgO was 20 to 40. In this case, the throughplane thermal conductivity was as high as 3.5 W/m·K. A higher weight ratio of BN to MgO usually led to poorer mechanical and flowing properties.

Key words: poly(decamethylene terephthalamide), boron nitride, magnesia, synergistic effect