Rapid Catalytic Recycling of Poly(ethylene terephthalate): Minimal Hydroxide, Minimal Biomass‐Derived Recyclable Cosolvent

Furfuryl alcohol is shown to serve as a biomass-based cosolvent par excellence for the alkaline hydrolysis of poly(ethylene terephthalate) (PET) bottle and PBA-PC compact disk waste. The solvent can be recycled, used at low levels (3 mL g⁻¹ PET), and operates in tandem with an efficient phase transfer catalyst to completely depolymerize PET at <100 °C in 10 min.

The rapid hydrolysis of poly(ethylene terephthalate) (PET) waste using sodium hydroxide, a phase transfer catalyst and furfuryl alcohol is demonstrated in 10 min at 98.5 °C. The cosolvent is biodegradable, available from biomass-based sources and outperforms a range of commonly used protic and polar aprotic cosolvents. Such is the competence of the cosolvent for this purpose that waste is minimized—for the first time minimal hydroxide (2.1 eq.) is employed and the solvent volume is limited to just 3 mL g⁻¹ PET (of which only 20% by weight is the organic component). It is found that the medium is compatible with phase transfer catalysis and a promoter incorporating aromatic units is superior (at 1 mol% loading) to previously optimal dimethyldialkylammonium halides. The medium can be recycled and reused after distillation at <100 °C, and furfuryl alcohol is also shown to serve as a cosolvent par excellence for the catalytic hydrolysis of poly(bis-phenol A carbonate) waste from compact disks under literature conditions.

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