Thiol-epoxy reactions were first exploited as a simple method for the preparation of recyclable cross-linked hydroxythioether particles with tunable structures.
The dynamic nature of supramolecules makes them useful in the fields of smart devices. The combination of multiple dynamic interactions in one material may bring some enhanced properties in mechanical property, self‐healing property, or recyclability. Thus, it is significantly meaningful to design new materials with multi‐dynamic bonds and clarify their bonding mechanisms. Here, a novel three‐armed polymer based on benzene‐1,3,5‐tricarboxamide (BTA) is developed and the polymer could be further complexed by metal ions to form dynamic zinc–imidazole interactions. In this system, BTA is located in the center, and the ligand‐functionalized monomer is copolymerized with n‐butyl acrylate to form three chains. This is the first time BTA is introduced to a self‐healing system to endow the polymer with assembly and self‐healing properties. The composition, chemical structure, assembly behavior, mechanical properties, and self‐healing properties of the polymer are investigated. It is revealed that the assembly behavior of the polymer depends on the BTA contents and time. The mechanical property can be easily tuned by ligand/metal ratio and is significantly adjusted by the polymer chain length and environment humidity. Long polymer chains not only contribute to good mechanical property but also promote the self‐healing process due to the effective physical entanglement.
Polyurethane elastomers with mechanical robustness, tear resistance, and healing efficiency hold great potential in wearable sensors and soft robots. However, achieving excellent mechanical properties and healable capability simultaneously remains highly desirable but exclusive. Herein, we propose a straightforward procedure for double modification of poly(urethane-urea) (PUU) via thiolactone chemistry, and two different dynamic cross-linking bonds (disulfide linkages and Zn 2+ /imidazole coordination) are successively incorporated into the side chain of PUU, producing double cross-linking elastomers (PUU−I/Zn−S). The synergy between disulfide linkages and Zn 2+ /imidazole coordination forms a robust and dynamic network, endowing PUU−I/ Zn−S with excellent mechanical and healing properties. The tensile stress, elongation at break, and toughness of the resultant elastomer can reach 44.06 MPa, 1000%, and 181.93 MJ m −3 , respectively. Meanwhile, PUU−I/Zn−S exhibits outstanding tearing resistance with a tearing energy of 42.1 kJ m −2 . The PUU−I/Zn−S can restore its mechanical robustness after self-healing at room temperature (25 ± 2 °C) or 60 °C and even maintain 91% of its original tensile strength after reprocessing two times. Additionally, PUU−I/Zn−S-based strain sensors are fabricated by introducing conductive nanofillers and demonstrate remarkable sensing capability to diverse human body motions. This work demonstrates a simple and feasible method for the postfunctionalization and enhancement of polyurethane and provides some insights into reconciling the traditional contradictory properties of mechanical robustness and healing efficiency.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.