Enhanced thermal–mechanical properties of polymer composites with hybrid boron nitride nanofillers

The present work focuses on the investigation of the thermal–mechanical properties of the epoxy composites with hybrid boron nitride nanotubes (BNNTs) and boron nitride nanosheets (BNNSs). The stable dispersions of BNNTs–BNNSs were achieved by a noncovalent functionalization with pyrene carboxylic acid. The resulting epoxy/BNNTs–BNNSs composites exhibited homogeneously dispersed BNNTs–BNNSs and a strong filler–matrix interface interaction. The composites showed a 95 % increase in thermal conductivity and a 57 % improvement in Young’s modulus by addition of only 1 vol. % BNNTs–BNNSs. Meanwhile, the composites also retained a high electrical resistance of pure epoxy. Our study thus shows the potential for hybrid BNNTs–BNNSs to be successfully used as the nanofillers of polymer composites for applications in electrically insulating thermal interface materials.