Efficient Hydrolysis of Polyethylene Terephthalate and Product Extraction Using an Aqueous Two-Phase System

Abstract

Polyethylene terephthalate (PET) has led to significant resource waste and environmental pollution due to inadequate recycling efforts. In this study, we developed a mild and efficient method for PET hydrolysis and product extraction. Upon an aqueous two-phase system (ATPS) composed of PEG600/KOH/H₂O, PET can be degraded at 90 °C with a conversion of 99.70% after 10 min and a terephthalic acid (TPA) yield of 95.86%. This is attributed to the introduction of PEG600 in the ATPS, which enhanced the solution penetration and alkali efficacy. Notably, this ATPS allows the spontaneous enrichment of degradation product into one phase, which thereby simplifies the product separation. Furthermore, the reaction solution can be recovered for more than 5 times. This work provides a promising approach for efficient PET degradation and product separation, contributing to the industrial recycling of PET waste.