Biobased, self-healing, and recyclable polyurethane derived hydrogel-elastomer hybrids for efficient lubrication

Developing biobased hydrogel-elastomer hybrids with stable lubrication derived from self-healing and recyclable polymer matrix poses a key challenge in the field of medical devices. Herein, we reported a novel hydrogelelastomer hybrid incorporating a tung oil (TO)-based, self-healing, and recyclable polyurethane (PU) substrate that exhibits exceptional hydrophilic and lubricating properties. Initially, a series of UV-curable PU elastomers containing dynamic hindered urea bonds (HUBs) derived from renewable TO were prepared. By adjusting the ratios of the cross-linking agent TO-based polyol and the chain-extending agent polytetramethyleneglycol, the mechanical and thermal properties of these elastomers could be tuned well. The as-prepared PU elastomers demonstrated remarkable dynamic properties, attributed to the dissociation and recombination of HUBs, enabling efficient self-healing and effective recycling through solvent or hot-pressing methods while preserving their mechanical properties. Furthermore, functional hydrogel-elastomer hybrids were obtained by applying UVinitiated polymerization method to generate hydrogel coatings onto the optimized PU elastomer surface. Compared to the pristine PU material, the resulting hydrogel-elastomer hybrids exhibited excellent lubricity in aqueous environments, resulting from the formation of a robust hydration layer facilitated by electrostatic forces. Overall, our current research work provides key design inspiration for developing next-generation medical devices from sustainable and recyclable functional biomaterials.