Upcycling Plastic Waste into High-Performance Supramolecular Adhesives via Titanium-Catalyzed Molecular Reconstruction

The development of eco-friendly adhesives derived from plastic waste and biomass resources presents a sustainable alternative to conventional petroleum-based adhesives, simultaneously addressing plastic pollution and the energy crisis. In this work, we employ solvent-free bititanium catalysis to convert waste polyethylene terephthalate (PET), polyethylene glycol (PEG), and glycerol into hyperbranched functional adhesive precursors. These precursors are subsequently combined with biobased methyl gallate via one-pot transesterification to produce high-performance adhesives (PETA). PETA demonstrates remarkable adhesion strength, achieving up to 14.8 MPa for steel bonding at ambient temperature. The end-functionalized hyperbranched multiblock structure of PETA confers outstanding thermomechanical and viscoelastic properties, enabling robust adhesion to diverse substrates, including steel, aluminum, brass, and wood. It also shows exceptional heat resistance (100 °C, 10 MPa), low-temperature tolerance (−184 °C, 2.8 MPa), stable underwater adhesion, and excellent reusability (88% strength retention after ten cycles). This study presents a viable strategy for upcycling plastic waste into high-value functional materials, advancing sustainable manufacturing.