Mechanically Robust Super‐Lubrication Polycarbonate‐Polyurethane (PCU) Enabled by Design of Dynamic Mechanics Network and Manufacture of Constrained Hydrogel Coating

Abstract Natural meniscus exhibits synergistic functions of load‐bearing, stress dissipation, and lubrication. Although synthetic materials show great potential for meniscus replacement, simultaneously exhibiting superior mechanical properties and robust super‐lubrication characteristics remains a significant challenge. Herein, a novel PCU material is developed that realizes exceptional mechanical robustness and ultralow friction through the synergistic integration of a dynamic 2‐ureido‐4[1H]‐pyrimidinones(UPy) hydrogen bond network within the bulk phase and a constrained hydrated‐hydrogel coating on the surface. UPy is chemically incorporated into the PCU synthesis, resulting in excellent load‐bearing capacity, high elastic modulus (45.2 MPa), and extraordinary fracture energy (96.996 kJ m −2 ) of PCU‐UPy. Subsequent manufacture of the entangled hydrogel coating on the surface of PCU‐UPy endows it with excellent hydration lubrication capacity. Due to the strong covalent combination and interpenetrating behavior between the hydrogel network and the PCU‐UPy matrix, the entangled hydrogel coating shows high bonding strength (toughness: ≈960 J m −2 ) and stable mechanical modulus in a long‐term physiological environment. The PCU‐UPy‐Hydrogel exhibits an ultralow coefficient of friction (COF: ≈0.0095) during 30 000 sliding cycles under a normal load of 10 N against stainless steel pins, superior wear resistance, low cytotoxicity, and implant biosafety. This work provides a new solution for developing high‐performance implantable prosthesis materials.