Tough Self-Healing Elastomers Based on the Host–Guest Interaction of Polycyclodextrin

Abstract

Inspired by animal muscles, we developed a kind of tough elastomers combining high strength and high stretchability with autonomous self-healing capability. A key structural feature is the construction of a double network (DN) connected by the hydrogen bond and host−guest interactions. The first network is the classic elastomer polyacrylate matrix cross-linked by strong hydrogen bonding. The second network is formed through the host−guest interactions between polycyclodextrin and the adamantane (Ad) groups on the side of the polyacrylate chain. Supramolecular interactions between two networks make them miscible and interpenetrate in the molecular level and then can share the load as the sample was stretched. The host−guest interactions act not only as sacrificial bonds for energy dissipation but also as self-healing driving forces. The tensile strength of the DN elastomer reaches about 6.7 MPa and the strain is as high as about 950%. The DN elastomer can be easy to repair by touching the damaged surface together at ambient conditions when broken or cut. The recovered tensile strength can reach over 4.5 MPa, which is better than the most pristine strength of existing spontaneous self-healing elastomers.

Design Principles of Interfacial Dynamic Bonds in Self‐Healing Materials: What are the Parameters?

“…The hierarchically structured fibers were suggested to arise from the complex combination and interactions of "hard" and "soft" phases within the SPCH and its constituents. Recently, Hou et al [153] 2019, developed tough elastomers with a combination of high strength and autonomous selfhealing capability. Here, the polyacrylate elastomer matrix was cross-linked by strong H-bonding and host-guest interactions between polycyclodextrin and the adamantine (Ad) groups on the polyacrylate side chain.…”

Development of a Strong, Recyclable Poly(dimethylsiloxane) Elastomer with Autonomic Self‐Healing Capabilities and Fluorescence Response Properties at Room Temperature

“…This challenge, that is, realizing the synchronous optimization of mechanical properties, self-remediation, and recyclability of materials, has not yet been solved. In recent years, researchers have developed multiple dynamic bond collaborative strategies [43][44][45][46] that combine two types of dynamic bonds (for example, combining metalligand interactions with hydrogen-bonding interactions [47] or disulfide metathesis with hydrogen-bonding interactions [48] ) to improve the robustness or stretching performance of self-healing materials. However, state-of-the-art self-healing materials are still not good enough because most materials produced using current design strategies are typically either tough but brittle or stretchable but weak.…”

Recent progress in self-healing polymers and hydrogels based on reversible dynamic B–O bonds: boronic/boronate esters, borax, and benzoxaborole

“…These materials show active non-covalent, supramolecular interactions, such as hydrogen bonding, [9][10][11][12][13] dipole interactions, 14 π-π interactions, 15,16 metal complexation, 17 and host-guest interactions. 18 The mechanism of self-healing using supramolecular attractions is described as follows. When the non-covalent bond is broken by external shock, the force acts between the supramolecular chains present at the fracture site, resulting in self-assembly.…”