Reinforcement of Hydrogenated Nitrile Elastomer With Polydopamine‐Functionalized Chitin Nano‐Whisker for Superior Mechanical and Heat Resistance Properties

ABSTRACT Chitin nano‐whisker (CNW) with excellent biocompatibility and high strength and high modulus can be used as a reinforced filler for polymer nanocomposites. Nevertheless, the intramolecular hydrogen bonds formed by the abundant hydroxyl groups on the surface of CNW make it extremely prone to agglomeration within the polymer matrix. Herein, functionalized CNW (PDA@CNW) with loose structural arrangement was fabricated through coating CNW with polydopamine (PDA). Then, PDA@CNW was applied as a reinforced agent for preparing the hydrogenated nitrile rubber (HNBR) nanocomposite via mechanical mixing and solution methods. Compared with the same amount of CNW, PDA@CNW endows HNBR with better performances. For example, when the filler content is 3 phr, HNBR/PDA@CNW composites present remarkable tensile strength of 7.6 MPa (improved by 499.2%), elongation at break of 517% (enhanced by 159.8%), right tear strength of 15.9 kN/m (increased by 79.3%), and thermal stability. Moreover, PDA@CNW can be uniformly dispersed in the HNBR matrix and has better interfacial interaction. Therefore, PDA@CNW exhibits great potential in the preparation of high‐performance elastomer composites, especially high‐strength elastomer. This research not only provides an effective strategy to overcome the problem of nanoparticle agglomeration but also opens a new way for the development of environmentally friendly and high‐performance bio‐based rubber composites.