Upcycling Waste PET Into Ionic Liquid‐Derived Small‐Molecule Adhesives

Abstract

ABSTRACT The chemical upcycling of polyethylene terephthalate (PET) presents a critical pathway toward a circular plastics economy, yet existing methods are often hampered by high energy demands and downcycled products. Herein, we report a catalyst‐ and solvent‐free aminolysis strategy that depolymerizes waste PET into a versatile molecular precursor under mild conditions. This precursor is subsequently engineered into a series of low‐molecular‐weight ionic adhesives via strategic functionalization and supramolecular assembly. By leveraging a rich network of noncovalent interactions, such as hydrogen bonds and electrostatic forces, these materials achieve remarkable cohesion and interfacial adhesion. An alkoxy‐functionalized variant demonstrated an adhesion strength of 12.4 MPa on glass, ranking among the strongest small molecular‐based supramolecular adhesives reported. This work establishes a sustainable paradigm for converting waste polyester into value‐added functional materials, bridging the gap between plastic pollution and high‐value manufacturing, promotes the circular economy.