Flexible and Robust Functionalized Boron Nitride/Poly( p -Phenylene Benzobisoxazole) Nanocomposite Paper with High Thermal Conductivity and Outstanding Electrical Insulation

Highlights m -BN/PNF nanocomposite paper with nacre-mimetic layered structures prepared via sol–gel film transformation approach presents excellent thermal conductivity, incredible electrical insulation, outstanding mechanical property and thermal stability. When the mass fraction of m -BN is 50 wt%, m -BN/PNF nanocomposite paper exhibits excellent thermal conductivity and electrical insulation. The λ ∥ and λ ⊥ are 9.68 and 0.84 W m −1 K −1 , and the volume resistivity and breakdown strength are as high as 2.3 × 10 15 Ω cm and 324.2 kV mm −1 , respectively. The m -BN/PNF nanocomposite paper with 50 wt% m -BN also presents outstanding mechanical properties (tensile strength of 193.6 MPa) and thermal stability (thermal decomposition temperature of 640 °C).