Dynamic covalently bio-based polyurethane-boron nitride nanosheet composites for effective self-healing and thermal management

Polymer-based composites, such as polyurethane-based composites, provide better corrosion and fatigue resistance than other materials, but their poor thermal conductivity limits their application areas. In this study, using boron nitride nanosheets (BNNSs), cardanol (CA), and 2-hydroxyethyl disulfide (HEDS) as raw materials, we have developed an innovative dynamically covalently crosslinked bio-based polyurethane thermal management composite filled with BNNSs, which takes into account the sustainability of the bio-based polyurethane and the excellent thermal conductivity of BNNSs. We further explored the effect of different BNNSs content ratios on the material properties, and we found that the thermal conductivity could improve by 156 % at 10 wt% BNNSsdoping. Meanwhile, the dynamic covalent cross-linking strategy endows the material with self-healing ability after physical damage. Incorporating disulfide bonds allows the samples to be dynamically reversible at certain temperatures to repair material damage and remodel for recycling. The development of this material offers a new approach to enhancing the performance of bio-based polymer materials. It provides a new avenue for designing and applying eco-friendly materials with high thermal conductivity.