Simultaneous Improvement of Mechanical Strength, Toughness, and Self‐healability of Elastomers Enabled by F─H‐Bond‐Based Nanoconfinement

Abstract There are often trade‐offs among high mechanical strength, high toughness, and efficient self‐healing. Herein, we present a biomimetic strategy utilizing F─H bonds for nanoconfinement to achieve the simultaneous enhancement of these conflicting properties. The mechanical strength, toughness, and self‐healing efficiency of a fluorinated crosslinked poly(urethane‐urea) (CPUU‐FA) elastomer are improved 1.3‐, 1.5‐, and 1.2‐fold, respectively, compared with those of its nonfluorinated counterpart. Notably, the CPUU‐FA has the highest recorded puncture energy (887 mJ) among polymeric elastomers and the highest fracture energy (117 kJ m −2 ) among reported thermoset elastomers. Moreover, it exhibits excellent self‐healing efficiency (99%), remarkable reprocessability, and a low surface energy (56 MJ m −2 ). The application of self‐healing elastomers in the fabrication of soft electronics is further demonstrated. The molecular design strategy is anticipated to inspire new developments in high‐performance materials for cutting‐edge applications.