Supramolecular Materials Cross-Linked by Host–Guest Inclusion Complexes: The Effect of Side Chain Molecules on Mechanical Properties

Abstract

Functional polymeric materials constructed by noncovalent bonds have attracted considerable attention due to their beneficial stretching and self-healing properties. We chose host–guest interactions using cyclodextrins (CDs) as host molecules to realize supramolecular materials with stretching and self-healing properties. Notably, an inclusion complex of a CD and a guest molecule functions as a reversible bond in a material. Herein, we studied the relationship between the mechanical properties of the materials and host–guest interactions based on the association constants of CDs with guest molecules and molecular structures of the guest molecules. A chemically cross-linked poly(acrylamide) gel showed high rupture stress, although the rupture strain was noticeably low. However, the host–guest hydrogels (CDAAmMe-R hydrogels) exhibited a higher rupture stress and strain of approximately 1000%. These rupture stress and strain values were related to the association constants of the CDs with guest units on the ...