Construction of TPU/m-BN composite materials by dual modification method to simultaneously improve thermal conductivity and mechanical properties

With the increasing integration of electronic devices, the role of filled high thermal conductivity composites in the field of thermal management has become more and more important. Although high filler content can obtain ideal thermal conductivity, it will deteriorate their mechanical properties. Therefore, how to synchronize the thermal conductivity and mechanical properties of composites is an urgent problem to be solved at present. In this study, TPU/m-BN composites with high thermal conductivity and good mechanical properties were successfully prepared by using TPU as the matrix, BN was modified with dopamine and complexed with Fe3O4, and then secondary modified with dopamine. The m-BN (BN/Fe3O4/PDA) were obtained as fillers using the dual modification method. The results showed that the TPU/m-BN composites had good thermal conductivity and could reach the equilibrium temperature within 20 s at the earliest. In addition, it had high thermal stability, thermal decomposition temperature up to 280 degrees C, and resistivity up to 6.77 x 107 Omega center dot mm. Especially important was that its tensile strength was 6.49 MPa, which was 134.3 % of that of pure polyurethane. In summary, the TPU/m-BN composites had good overall performance and had the potential to solve the problem of heat dissipation in aerospace and electronic circuits.