Multifunctional Polyurethane Exhibiting High Mechanical Performance and Shape-Memory-Assisted Self-Healing

Abstract

Polymeric materials often face inherent trade-offs between mechanical performance and self-healing capabilities, which presents significant challenges to their development and practical application. Here, an effective strategy is reported to overcome these limitations. By introducing a highly crystalline polyol—characterized by its chain folding and storage chain length—and coordination bonds into polyurethane, an exceptional balance of high tensile strength (47.18 ± 2.35 MPa), exceptional elongation at break (5952.72 ± 254.20%), outstanding toughness (1396.39 ± 90.05 MJ m⁻³), and high hardness (shore D hardness 43.8 ± 0.8) is achieved, while also maintaining intrinsic self-healing properties. The material's self-healing is facilitated by the water solubility of polyol (polyethylene glycol, PEG), which enables rapid healing and welding at low temperatures (4 °C) with the aid of water. Additionally, the shape-memory recovery force further enhances crack closure and healing, contributing to the material's durability. This unique combination of mechanical performance and self-healing capabilities underscores the potential of this material for advanced applications that require both high mechanical properties and robust self-healing functionality.