A Supramolecular Polymer Formed by Small Molecules

Abstract

Supramolecular polymers are intriguing due to their thermal reversible and stimuli-responsive properties. However, most supramolecular polymers reported thus far have poor mechanical properties due to the low bonding energy of the non-covalent interactions. Here, we report a supramolecular polymer that is formed by small molecules, ethylene glycol- bis (2-aminoethylether)- N,N,N ′ ,N ′-tetrapropionic acid (EGTPA). Owing to the dense hydrogen bonding and low crystallinity, this material exhibits polymer-like properties—in other words, high mechanical strength and excellent plasticity. Thermal and environmental control over the dynamics of hydrogen bonding leads to many intriguing properties, such as thermal healing and tunable mechanical strength, in a way that is not accessible by traditional polymers. Based on these features, we further demonstrate its application in shape memory hybrids. Significant shape memory effect is observed, although neither of the components of the hybrids show the shape memory effect individually. A rigid supramolecular polymer is formed by small molecules The polymer can be healed under mild conditions Stiffness is modulated by varying the temperature and humidity Shape memory effect based on tunable stiffness is demonstrated Zhang et al. report a supramolecular polymer formed by small molecules. Due to the dense hydrogen bonding and low crystallinity, this material exhibits high mechanical strength and plasticity. The thermal and environmental control over the dynamics of hydrogen bonding leads to the observation of thermal healing and tunable stiffness.