Abstract: Pre-treating a waste polyester material with dichloromethane (DCM) produce purified polyester for reuse. The purified polyester can be recycled via any chemical or mechanical recycling process. Where the waste polyester material includes non-polyester contaminants, the DCM-treated polyester material produces a slurry that includes the DCM, a solid component that includes a polyester monomer product for reuse, and a waste liquid component where the non-polyester contaminants can be filtered from the top of the liquid component.

Abstract: A waste polyester material is prepared for recycling by dissolving the material in a solution comprising hexafluoroisopropyl (HFIPA) and a chlorinated hydrocarbon, such as dichloromethane (DCM) and/or an aromatic hydrocarbon, such as toluene or xylene, to form a dissolved polyester sample. The dissolved polyester may be prepared for recycling by evaporation, spray drying, and/or precipitation, which produces a purified solid polyester product. The dissolution solution, which is separated from the purified solid polyester product, is also recycled through distillation with purification.

Abstract: A depolymerization reaction of a polyester input with an organocatalyst and an alcohol solvent produces (i) a recycled monomeric or oligomeric diester from the polyester, (ii) the organocatalyst for reuse, and (iii) the alcohol solvent, which may also be reused. The presence of volatile impurities, such as water, acetyl aldehyde, and organic solvents can interfere with the success of the depolymerization reaction. A pre-reaction distillation step removes volatile impurities from the polyester input resulting in an efficient depolymerization reaction with consistency among batches. The polyester input may be further treated with a water azeotrope to remove water from the polyester input prior to the pre-reaction distillation.