High-Strength and Excellent Self-Healing Polyurethane Elastomer Based on Rigid Chain Segment Reinforcement

Owing to their extensive application scope, elastomers that combine high strength and excellent self-healing efficiency have always attracted significant attention and are still a contradiction. In this study, a novel PU elastomer was prepared by combining rigid poly(amic acid) (PAA) chain segments and 3,3-dithiodipropionic dihydrazide (DPH) containing sextuple hydrogen-bonding units and disulfide bonds. The prepared elastomer exhibited a high tensile strength of 50.1 MPa and a high toughness of 144.2 MJ/m3. The rigid PAA chain segments serve as a rigid framework, significantly enhancing the mechanical strength of the elastomer. Meanwhile, DPH with sextuple hydrogen-bonding units and disulfide bonds enabled the elastomer to exhibit an excellent self-healing efficiency of 96.1% after 12 h at 80 °C. Additionally, the strong and reversible cross-linking of the hydrogen-bonding arrays in the elastomer endows it with excellent mechanical strength, self-healing ability, and recyclability, allowing it to be recycled after hot pressing and dissolution.