Construction and Mechanical/Tribological Properties of Ordered Fiber Reinforced Hydrogel

Hydrogels with high water content, excellent permeability and biocompatibility are widely used in the biomedical field. However, traditional hydrogels often present a trade-off between mechanical strength and lubrication performance, making it challenging to meet the stringent demands of high-toughness applications, such as substitutes for cartilage and skin. In this study, a kind of ordered structure reinforced 3PC-C gel with high water content, high strength, low friction and fatigue resistance was developed through molecular network design, combined with temperature field induced orientation and fiber reinforcement technology. This hydrogel featured a staggered, orderly oriented honeycomb network structure with dense porosity, exhibiting significant enhancements in mechanical properties: a compressive strength of 10.1 MPa, compressive modulus of 7.5 MPa, tensile strength of 11.4 MPa, tensile modulus of 28.6 MPa and fracture toughness of 34 MJ/m³. Furthermore, the orderly staggered network structure and the inclusion of CF provided efficient channels for liquid extrusion, supplying lubrication to the friction surfaces and reducing the coefficient of friction to 0.038—a reduction of 18% compared to the unoriented 3PC-C gel (0.046). And the friction coefficient exhibited a trend of decreasing first and then increased with increased load and progressively reduced with increased sliding speed. Moreover, the enhanced structured 3PC-C gel also demonstrated excellent resistance to crack propagation and compressive fatigue, along with improved tribological stability. After enduring one million fatigue compression cycles, its compressive strain only reduced by 1.9% (14.0%-15.9%), significantly lower than that of unoriented hydrogels unoriented 3CF (18.5%~20.8%) and 0CF 3PC-C gel (21.1%~22.24%). These results further validated that the CF and the staggered orderly structure significantly enhance the mechanical energy dissipation, self-recovery, and dynamic load-bearing capacity of the composite hydrogel. In conclusion, the ordered structure reinforced 3PC-C gel, with its superior mechanical strength and tribological performance, presented promising new applications in biomedicine and soft material devices.