Ultra Strong and Tough Bio‐Based Polyurethane Elastomers with Rigid‐Flexible Hybrid Soft Segment Supramolecular Cross‐linked Networks

Abstract High‐intensity exercise is prone to cause damage to articular cartilage and ligament tears. The existing polyurethane elastomers still face challenges such as poor mechanical strength and insufficient biocompatibility in biomedical load‐bearing materials, which hinders their clinical application. Herein, a strategy based on rigid‐flexible hybrid soft segment supramolecular cross‐linking is proposed to prepare ultra strong and tough bio‐based polyurethane elastomers (BPUs). Rigid polylactic acid polyol (PLA) and flexible poly(1,3‐propanepolyol) polyol (PO3G) are used as the hybrid soft segment. Among them, the crystalline region of PLA enhanced the mechanical strength of the elastomer, and the conformational entropy buffering effect of flexible PO3G reduced the phase interface energy, promoting the spatial uniformity of the microphase separation structure of the elastomer. Meanwhile, a supramolecular hydrogen bond dynamic network is introduced to achieve efficient energy dissipation under stress induction. The developed BPUs has excellent mechanical properties (tensile strength: 82.29 MPa, elongation at break: 2128%, toughness: 993.08 MJ m ⁻³ ) and biocompatibility. In addition, BPUs are processed into artificial ligaments through 3D printing technology, which have stable mechanical properties and fatigue resistance in a liquid environment. Therefore, this high‐performance sustainable elastomer has great application potential in the field of biomedical load‐bearing (e.g., tendons and ligaments).