Healable, Strong, and Tough Polyphenol-Based Polyurethanes Engineered via Synergistic Reversible Cross-Linked Microphase: Breaking the Performance Trilemma for Artificial Ligaments

Achieving a harmonious balance among healability, high mechanical strength, and exceptional toughness remains a persistent and formidable challenge in the development of artificial ligaments. Herein, we report a class of polyphenol-based reversible cross-linked polyurethanes (RCPUs) designed to overcome this long-standing performance trilemma. By synergistically integrating dynamic hydrogen bonds, phenolic urethane bonds, and finely engineered microphase separation structures, the RCPUs achieve an exceptional combination of mechanical robustness, self-healing capability, and antibacterial activity. The optimized RCPU_1.8 demonstrates a tensile strength of ∼57.5 MPa and toughness of ∼323.8 MJ m^-3, along with a healing efficiency of ∼88.1% after 12 h at 75 °C. Furthermore, a simple prestretching treatment significantly enhances the tensile strength to ∼167.7 MPa while maintaining excellent fatigue resistance over 100 loading cycles. This work provides a scalable and synergistic strategy for developing next-generation multifunctional artificial ligaments with well-balanced performance.