Self-Healing Polyurethane Elastomers with High Mechanical Properties Based on Synergistically Thermo-Reversible and Quadruple Hydrogen Bonds

It is still challenging and attractive to prepare polyurethane (PU) materials with excellent self-healing ability while improving their mechanical properties and high ductility. Here, a multifunctional linear PU supramolecular elastomer was successfully prepared by introducing a cross-linking network of quadruple hydrogen bonds and thermo-reversible Diels–Alder bonds and rigid ring structure to the linear backbone. The results exhibited that the obtained PU elastomer displayed a high tensile strength (6.30 MPa), elongation (1957.84%), toughness (84.48 MJ/m3), and excellent repair efficiency (93.33%). The quadruple hydrogen bonds from 5-(2-hydroxyethyl)-6-methyl-2-aminouracil and thermo-reversible Diels–Alder bonds from the conjugated reaction of 4,4′-bismaleimide diphenylmethane with furfuryl alcohol, due to its synergetic dual reversible bonds, formed the PU elastomer that possessed excellent mechanical, self-healing, shape recovery, and reprocessing properties. The prepared multifunctional PU can be used as a substrate for flexible conductive materials or as conductive composite material with conductive materials, which can self-repair many times when the surface is damaged, can be recycled, and greatly improve the service life of the material. Therefore, the prepared multifunctional high-performance self-healing PU materials have potential applications in several fields.