Design of Polyurethane Based on a Dual-Repair Mechanism of Dynamic Disulfide Bonds and Hydrogen Bonds

Abstract

Self-healing polyurethane can ensure the operational stability of flexible strain sensors. However, achieving efficient self-healing at room temperature while simultaneously maintaining a high mechanical toughness remains a significant challenge. Here, we have proposed a molecular design driven simultaneously by dynamic disulfide bonds and hydrogen bonds and introduce Penta-EG into the main chain structure of polyurethane to form a certain hierarchical hydrogen bond structure and improve biocompatibility. Based on this design, we have successfully fabricated an elastomer that is self-healing and tough at room temperature. After healing at room temperature for 24 h, the healing efficiency of this elastomer reached 74.35%, and it exhibited excellent mechanical properties (a tensile strength of 4.64 MPa, an elongation at break of 1670%, a tear energy of 15,492.9 J/m2, and a puncture energy of 125.3 mJ). Moreover, the prepared strain sensor possessed high sensitivity and could be applied to detect human movement.