Mechanically responsive self-reinforced polyurethane elastomers with cyclodextrin metal-organic framework structure for high impact resistance

Polyurethane (PU) elastomers are widely used in many fields due to their distinct performance advantages. With the broadening of its application domains, the enhancement of its performance and the diversification of its functions have become major research priorities. Here, a mechanically responsive self-reinforced elastomer based on polyurethane matrix and cyclodextrin metal-organic framework structure is prepared by a simple one-pot synthesis. The introduction of cyclodextrin metal-organic frameworks (CD-MOFs) not only constructs the interfacial hydrogen bonding network, but also synergistically triggers the strain-induced crystallization (SIC) self-enhancement effect in polyurethane elastomers. The resulting material exhibits desirable tensile strength (up to 43.21 MPa), excellent elongation at break (1451.13 %), outstanding fracture energy (367.23 kJ/m²) and good impact resistance (2.80 MJ/m³). The exceptional mechanical properties are mainly due to the unique structure of MOF, energy dissipation of hydrogen bonding and strain-induced crystalline self-reinforcement. This study provides a new idea for the development of polyurethane elastomers with metal-organic framework structure, and offers great possibilities for use in vibration damping, energy absorption and impact resistance.