Synergistic Supramolecular Activation and Dynamic Alkalinity Replenishing for Sustainable Recycling of...

Although alkaline hydrolysis represents a promising strategy for recycling polyester plastics, its practical deployment is hampered by the alkaline paradox: the excessive alkaline solution is required to sustain reaction kinetics, while it leads to severe equipment corrosion and wastewater burdens. Here we demonstrate a solvent-induced alkaline self-replenishing strategy that enables efficient recycling of diverse ester-containing plastics, including thermosets (e.g., unsaturated polyester resin, epoxy resin, vinyl ester resin) and thermoplastics (e.g., PET, PBAT) under remarkably mild conditions. By exploiting the temperature-dependent solubility of KOH in 1,3-dimethyl-2-imidazolidinone (DMI), we established a dynamic alkaline balance: low solubility at room temperature confines it largely to the solid phase, whereas heating promotes dissolution that replenishes consumed base and prevents kinetic stagnation. Characterization evidence reveals that DMI acts as a molecular co-activator, forming supramolecular complexes with K⁺ to enhance OH^- nucleophilicity and polarize ester bonds simultaneously. This system allows for the easy recovery of KOH via auto-precipitation upon cooling, ensuring excellent reusability. Our work offers a universal and cost-efficient dynamic methodological framework for the sustainable recycling of diverse polymer architectures.