Depolymerization of Post-Consumer Polyethylene Terephthalate by Glycolysis Using Zinc Acetate Catalyst

Abstract

The growing accumulation of post-consumer polyethylene terephthalate (PET) waste has intensified environmental concerns and emphasized the need for sustainable recycling technologies capable of recovering valuable chemical intermediates. This study investigates the depolymerization of post-consumer PET through glycolysis using zinc acetate as a catalyst for efficient chemical recycling and monomer recovery. The glycolysis process was carried out under controlled reaction conditions to evaluate the influence of temperature, reaction time, catalyst concentration, and glycol-to-PET ratio on depolymerization efficiency and product yield. Experimental analyses demonstrated that zinc acetate effectively catalyzed the cleavage of ester bonds in PET, resulting in the formation of bis(2-hydroxyethyl) terephthalate (BHET) as the primary depolymerization product. The catalyst enhanced reaction kinetics and improved conversion efficiency by promoting uniform degradation of the polymer structure. Product characterization confirmed the successful recovery of high-purity glycolysis intermediates suitable for reuse in polymer synthesis and value-added chemical applications. Kinetic evaluation revealed that higher reaction temperatures and optimized catalyst loading significantly accelerated depolymerization while minimizing undesired side reactions and oligomer formation. The process also exhibited lower energy consumption and reduced environmental impact compared with conventional disposal and thermal treatment methods. Furthermore, the chemical recycling approach supports circular economy principles through the recovery and reutilization of polymer feedstocks from plastic waste streams. The findings highlight the potential of zinc acetate-catalyzed glycolysis as an effective and economically viable strategy for PET waste management and sustainable production of recycled polymer intermediates in industrial applications.