Thermoplastic Elastomers Biodegradable in All-Natural Environment with Nanoclusters Formed by Intermolecular Hydrogen Bonding and Π-Π Stacking as the Physical Crosslinking Point

Abstract

Integrating excellent mechanical properties and biodegradability into thermoplastic elastomers is a long-term challenge. We prepared a novel thermoplastic elastomer poly (ethylene terephthalate-co-caprolactone) copolyester (PETCL), by molecular structure design basing on the non-covalent interactions between molecules. Using PET as the hard segment and PCL as the soft segment, the length and spatial distribution of the PETCL soft and hard segments can be tuned by adjusting the monomer ratio. As a result, it ultimately promotes the aggregation of specific structural units in three-dimensional space and form nanoclusters, because of the intrinsic hydrogen bonding and Π-Π stacking interactions in the benzene rings. The clusters act as a reversible physical cross-linking network, which endowed the material with excellent mechanical properties with excellent mechanical properties, resilience and tear resistance. In addition, the material has successfully achieved rapid degradation in typical natural environments, including soil and ocean. This work provides a new strategy for preparing biodegradable polyester based thermoplastic elastomers.

Keywords: Thermoplastic elastomer, Self-healing, Hydrogen bonding, Π-Π stacking, Biodegradable