A Bio-based healable/renewable polyurethane elastomer derived from L-Tyrosine/Vanillin/Dimer acid

Bio-based, healable, and recyclable polyurethane materials conform to the sustainability of the polyurethane industry. By introducing dynamic covalent bonds, the cross-linked polyurethane can obtain the performance of network rearrangement, thereby realizing self-healing and reprocessing. In this work, a self-healing/renewable polyurethane based on bio-based vanillin and tyrosine was successfully synthesized solvent-freely and catalysts-freely. Due to two different thermal reversible mechanisms, metathesis of imines and deblocking/re-blocking of phenolic urethanes, the obtained PU has considerable self-healing efficiency and renewability. At 120 °C, the surface scratches almost completely disappear within 90 min, and the tensile strength can be restored to ∼ 95% within 2 h. After remolded for 5 times, the chemical structure, glass transition temperature, deblocking behavior, tensile strength, elongation at break and gel content didn’t change significantly. Both the environmental friendliness of bio-based raw materials and the renewability of the obtained polyurethane materials meet the requirements of sustainability.