Highly Efficient Growth of Boron Nitride Nanotubes and the Thermal Conductivity of Their Polymer Composites

We developed a novel strategy for the gram-scale fabrication of boron nitride nanotubes (BNNTs). Li3N was used as the promoter: it not only catalyzes the BNNTs growth but also serves as the nitrogen source. BNNT/thermoplastic polyurethane (TPU) are flexible, transparent, and thermally conductive composite films that were also fabricated with an in-plane thermal conductivity of 14.5 W m–1 K–1 at 1.0 wt % BNNTs. This is an improvement of more than 400% over neat TPU. This study will enable BNNTs to be used in heat dissipation materials, high temperature components, and thermal protection systems.