Solvent switch strategy to facilitate the downstream process of chemical recycling of plastics

Polyethylene terephthalate (PET) is highly persistent in the environment, and current recycling strategies remain inefficient, particularly for textiles where polyester is interwoven with other fibers. Existing cosolvent-assisted methanolysis approaches allow mild reaction conditions but require large amounts of antisolvents for monomer recovery. Here, we report methyl acetate (MeOAc) as a cosolvent that enables rapid PET methanolysis within 1 h at 65 °C while simultaneously driving dimethyl terephthalate (DMT) precipitation in MeOH/MeOAc mixtures. This strategy affords 97 % DMT yield with >98 % purity through simple crystallization and filtration. DFT calculations show that MeOH/MeOAc blends enhance DMT desolvation and crystallization relative to conventional solvents. Crucially, monomer recovery occurs at room temperature without antisolvents or extended cooling, achieving a 29 % reduction in greenhouse gas emissions within a closed-loop framework. The method selectively depolymerizes PET from both pure polyester and blended textiles, underscoring its potential as a scalable and sustainable solution to PET waste accumulation.