Synergistic integration of dynamic acylsemicarbazide bonds and disulfide bonds into polyurethane: A facile strategy to surmount the tradeoff between mechanical strength and self‐healing capacity of elastomers

Abstract

AbstractThe polymeric materials can simultaneously possess high mechanical properties and outstanding self‐healing performance under mild condition have found widespread applications in various fields. However, this type of polymers is exceedingly rare due to the trade‐off between mechanical robustness and chain flexibility for healing. In this study, we designed a facile strategy for synergistic integration of dynamic acylsemicarbazide (ASC) bonds and disulfide bonds into polyurethane elastomer by the reaction between 3,3′‐dithiobis(propionohydrazide) and isocyanate‐terminated Pre‐PU. The obtained elastomer ASC‐SS‐PU not only possesses an outstanding tensile strength (17.1 MPa), good stretchability (735%) and high toughness (57.16 MJ·m−3), but also exhibits excellent self‐healing performance under mild condition. The healing efficiency of the damaged ASC‐SS‐PU samples (breakage rate >90%) can reach over 70% healing at 60°C for 40 min, which is much lower than conventional ASC‐based PU elastomer. Considering the simple and easy‐to‐scaleup preparation process and commercially available low‐cost raw materials, outstanding mechanical strength and toughness, as well as high healing efficiency under mild condition, the ASC‐SS‐PU elastomer as self‐healing but strong materials have great potential for use in various fields.