Modified boron nitride reinforced natural rubber composites and molecular dynamics simulation

Abstract For thermal conductive boron nitride (BN)/polymer composites, an overabundance of BN in the formulation may significantly impair the mechanical integrity, thereby restricting their applicability in practical scenarios. In this work, we introduced a novel modifying agent, which was grafted onto the exterior of BN following high‐temperature calcination. The resultant modified boron nitride demonstrated a marked improvement in the thermal conductivity and mechanical characteristics of natural rubber (NR) composites. Upon incorporating a filler content of 60 phr, the modified boron nitride NR composite achieved tensile strength, elongation at break, and thermal conductivity to 19.34 MPa, 1402%, and 0.735 W/mK, respectively, which represented an increase of 23.97%, 75.69%, and 33.15% over the BN/NR composite. The observed enhancement in mechanical properties and thermal conductivity of the composites is the contribution of the novel modifier grafting on the BN surface, which has notably improved the interfacial interaction with NR. In addition, the binding energy, solubility parameter, free volume fraction, and radial distribution function of BN/NR and modified boron nitride NR composites were analyzed by molecular dynamics simulation, which provided support for the interface reinforcement mechanism. This simple and versatile modification method introduced in this work can broaden prospects in the design of natural rubber composites. Highlights Successful synthesized of a new modifier with long chains. Interfacial compatibility of composites explained by combining molecular dynamics simulations. Effectively improved both the mechanical and thermal conductivity of the composites. Successful use of high‐temperature assisted modification to graft modifiers onto BN surfaces.