Perfluorocarboxylate Anion Bonding Strategy Driving Microphase Separation for Tailored Enhancement of Ionic Polyurethane Covalent Adaptable Networks

ABSTRACT Effectively mediating noncovalent interactions among polymer chains in covalent adaptable networks (CANs) is essential for attaining a synergistic improvement in both strength and toughness. Herein, a perfluorocarboxylate anions bonding strategy based on intermolecular ionic interactions and hydrogen‐bond interactions was proposed for synthesizing ionic polyurethanes ( Ionic‐PUs ) with enhanced mechanical properties and facile reprocessing capability. Specifically, a series of dimidazolium perfluorocarboxylate (F3–F9)‐based ionic chain extenders was designed and copolymerized into the polyurethane backbone, resulting in regulating microphase separation, energy dissipation, and dynamic responsiveness. It showed that the tensile strength, elongation at break, and toughness of the optimal sample CF 3 CO 2– –PU were enhanced to 2.40, 1.07, and 2.45 times than those of the control nonionic polyurethane DMG–PU , achieving synergistic enhancement of strength and toughness. Moreover, deep insights into the mechanisms governing the mechanical properties of Ionic‐PUs , which highlight the role of strong ionic interactions and minor steric hindrance in enhancing their mechanical performance. Benefiting from oxime‐urethane dynamic chemistry, Ionic‐PUs could be reprocessed via hot‐pressing or solvent treatment while maintaining the thermomechanical performance. Additionally, the perfluorocarboxylate anion bonding strategy could enhance the Ionic‐PUs dielectric properties. Intrinsic capacitive sensors fabricated from CF 3 CO 2 –PU demonstrated outstanding performance in motion signal monitoring and stress visualization.