Preparation of functionalized boron nitride nanosheets by one-step method for improving the thermal conductivity of polymers

Boron nitride nanosheets (BNNSs) with high thermal conductivity (TC) have promising applications in the thermal conduction. However, the preparation of BNNSs is cumbersome and BNNSs are prone to aggregation in the polymer matrix, which reduces the efficient enhancement for the TC of BNNSs/polymer composite. Herein, we propose a one-step method for the simultaneous exfoliation and functionalization of BNNSs with polymer latex as an agent. The obtained WPU-BNNSs displayed as few-layers with sizes of 100-500 nm and were mixed with WPU matrix as filler. The results demonstrated that the BNNSs/WPU composites have higher TC than the hBN/WPU with the same filler content. When the filler content reached 50%, its TC was 251.4% higher than that of pure WPU. The excellent TC arose from the outstanding dispersion uniformity of WPU-BNNSs in the matrix. This study provides an economical and efficient method of fabricating BNNSs-based thermal conductive composite materials.