Effect of polymer topology on non-covalently bonded polyesters

Synthetic polymers have a crucial role in our daily lives. The irreversible nature of covalent bonding in conventional synthetic polymers makes them non-recyclable and prevents re-processing of the materials. Throughout the years with the development in technology, the demand for more advanced materials such as, reversible, recycable, and re-processable materials has increased. Supramolecular chemistry has emerged to solve this need for reversibility in polymer materials. Supramolecular polymers are more tunable and dynamic due to their non-covalent and reversible nature. Non-covalent interactions include metal-ligand coordinations, host-guest, π – π stacking, ionic interactions and hydrogen bonding. Ionic hydrogen bonding has the known characteristics of hydrogen bonding such as directionality, strength and versatility. For instance, a carboxylic acid and an amine give rise to ionic hydrogen bonding by acid-base complexation reaction. Thus, carboxyl-terminated polyesters, in principle, may coordinate with amines to produce supramolecular materials. In this study, the carboxyl-terminated polyesters and amines having different functionalities were mixed/reacted in a melt reactor to form acid-base coordinates. The thermal and mechanical properties of the amine treated polyesters were investigated through DSC and rheometric measurements, respectively.