Thermal properties of polymer-derived ceramic reinforced with boron nitride nanotubes

We report the thermal properties of boron nitride nanotube (BNNT) reinforced ceramic composites using the polymer derived ceramic (PDC) processing route. The nano-composites had a BNNT loading of up to 35.4 vol.%. TGA results showed that nano-composites have good thermal stability up to 900 degrees C in air. BNNTs in nano-composites survived in an oxidizing environment up to 900 degrees C, revealing that nano-composites can be used for high temperature applications. Thermal conductivity of PDC reinforced with 35.4 vol.% BNNT was measured as 4.123 W/(m center dot K) at room temperature, which is a 2100 % increase compared to that of pristine PDC. The thermal conductivity value increases with the increase of BNNT content. A thermal conductivity percolation phenomenon appeared when the BNNT content increased to 36 +/- 5 vol.%. The results of this study showed that BNNTs could effectively improve the thermal conductivity of PDC materials. BNNT reinforced PDC could be used as thermal structural materials in a harsh environment at temperatures up to 900 degrees C.