A Solvent-Resistant and Biocompatible Self-Healing Supramolecular Elastomer with Tunable Mechanical Properties

The purpose of this work is to demonstrate a new design strategy to produce a self-healing supramolecular elastomer with solvent resistance and biocompatibility and tunable mechanical properties. This aim is successfully achieved by synthesizing a lignin-based supramolecular elastomer (LSE) through branching amide molecular chains on the lignin. The use of lignin effectively reduces the glass transition temperature and the degree of crystallinity of LSEs and generates urea-modified hydrogen bond groups to obtain self-healing capability. The synthesized LSEs behave as rubber and exhibit spontaneous self-healing behavior at room temperature without external stimuli. The mechanical and self-healing properties are closely related to the content of lignin. The elongation at break of the LSE-3 is 172% and tensile strength is 1.12 MPa, and achieves full recovery after a healing time of 48 h. The LSE material demonstrates insolubility in common polar solvents and is essentially noncytotoxic and potentially biocompatible for biomedical applications.