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

Area of Science:

• Materials Science
• Polymer Chemistry
• Sustainable Chemistry

Background:

• Chemical upcycling of polyethylene terephthalate (PET) is crucial for a circular plastics economy.
• Current PET recycling methods often require high energy input and result in lower-value products.
• Developing efficient and sustainable PET depolymerization techniques is essential.

Purpose of the Study:

• To develop a catalyst- and solvent-free method for PET chemical upcycling.
• To engineer waste PET into high-performance supramolecular adhesives.
• To establish a sustainable route for converting plastic waste into value-added materials.

Main Methods:

• Aminolysis of waste PET under mild, catalyst- and solvent-free conditions.
• Functionalization of the resulting molecular precursor.
• Supramolecular assembly to create low-molecular-weight ionic adhesives.
• Characterization of adhesive properties, including adhesion strength on glass.

Main Results:

• Successful depolymerization of PET into a versatile molecular precursor without catalysts or solvents.
• Creation of ionic adhesives through functionalization and supramolecular assembly.
• An alkoxy-functionalized adhesive achieved a high adhesion strength of 12.4 MPa on glass.
• Demonstrated remarkable cohesion and interfacial adhesion due to noncovalent interactions.

Conclusions:

• The developed aminolysis strategy offers a sustainable pathway for PET upcycling.
• Low-molecular-weight ionic adhesives derived from PET waste exhibit excellent performance.
• This work bridges plastic pollution challenges with high-value material manufacturing, advancing the circular economy.