A highly stretchable and self-healing hydroxy-terminated polybutadiene elastomer

The damage such as microcracks limits the application of hydroxy-terminated polybutadiene (HTPB) elastomer. Here, hydroxy-carboxy-terminated polybutadiene (HCTPB) and Fe3+ selected to facilitate ionic bonds (COO−⋯Fe3+) formation is proposed as a strategy to alleviate the intrinsic self-healing problem for HTPB elastomer. In typical HTPB polyurethane elastomer, the elongation at break is 997.3% while the tensile strength is 1.83 MPa, the damage cannot repair by intrinsic covalent or non-covalent, resulting in permanent damage. In contrast, HCTPB is able to offer COO−, entailing a COO−⋯Fe3+ ionic bonds. Incorporated 6 wt% HCTPB and Fe3+ into the HTPB elastomer elevates the tensile strength to 5.2 MPa, reducing the elongation at break in 877.8%. HCTPB and Fe3+ enhance the self-repair rate reaches up to 92% after repairing at 80 °C for 10 h after cutting for HTPB elastomer. This strategy has immediate implications for using COO−⋯Fe3+ ionic bonds to improve the performance of HTPB polyurethane elastomer devices.