A novel polyurethane elastomer with super mechanical strength and excellent self-healing performance of wide scratches

Abstract Great progress has been made in the research of self-healing materials in recent decades, however, there are still great challenges in achieving high mechanical strength and wide scratch healing simultaneously. Herein, a novel polyurethane elastomer (PUDA) containing polycaprolactone (PCL) soft segments and Diels-Alder (DA) adducting structure was specially designed and synthesized. The experimental results show that the PUDA elastomer after being trained not only had ultrahigh mechanical strength, but also had satisfactory ability in healing of wide scratches. It was found that the elastomer displayed a high tensile strength up to 32.88 MPa, which is unprecedented when compared to those reported self-healing elastomers. The PUDA elastomer material also had excellent healing ability towards wide scratches: an 80-μm-wide scratch could be completely healed after heating at 110℃ for 6 min. Furthermore, the elastomer material could also attain more than 100 % recovery of mechanical strength, with its recovered tensile strength reaching up to 34.58 MPa. The developed PUDA elastomer demonstrates quite promising perspective in material science and engineering field, especially for the protection of surface coating.