Hierarchical Hydrogen Bonding‐Enabled Rapid Room‐Temperature Self‐Healing Polyurethane for High‐Sensitivity Strain Sensors

A self‐healing polyurethane elastomer (IPDA_0.5‐PPGTD_1.0‐Urea_0.5) with good mechanical properties is prepared by changing the dynamic properties and hydrogen bond density of the hard segment units through a facile one‐pot poly‐condensation approach. Comprehensive characterization techniques are utilized to analyze the structure, performance, and self‐healing mechanism of IPDA_0.5‐PPGTD_1.0‐Urea_0.5. The findings reveal that the amorphous structure of the polymer network, coupled with the rapid dissociation–reassociation dynamics of hydrogen bonds and the inherent mobility of hard segment units, imparted IPDA_0.5‐PPGTD_1.0‐Urea_0.5 with exceptional mechanical properties, including a tensile strength of 1.92 MPa and an elongation at break exceeding 1600%. Notably, the mechanical performance achieves complete recovery within 12 h, accompanied by outstanding puncture and tear resistance. The types of hydrogen bonds in hard phase units are studied by two‐dimensional correlation Fourier‐transform infrared spectra, the dynamics of hydrogen bonds are investigated by variable‐temperature infrared and the dynamics of polymer chain segments are investigated by Arrhenius equation. Due to its excellent mechanical properties and self‐healing properties, IPDA_0.5‐PPGTD_1.0‐Urea_0.5 shows excellent application potential in self‐healing flexible conductors.