Closed-loop chemical recycling of polyethylene furan-2,5-dicarboxylate (PEF) under microwave-assisted heating

Abstract

Polyethylene furan-2,5-dicarboxylate (PEF) is a high-performance, bio-based analog to traditional petroleum-derived polyethylene terephthalate (PET). While the chemical recycling of PET has been well studied, PEF recycling studies are limited. This work investigated PEF depolymerization via heterogeneously catalyzed glycolysis using microwave-assisted heating. Various PEF polymers were characterized to understand how the molecular weight, crystallinity, and polymerization catalysts affect the depolymerization. The effects of the reaction temperature and PEF particle size were also studied. The glycolysis of PEF occurred at lower temperatures with faster overall kinetics compared with PET. Recovery of the PEF monomer, bis(2-hydroxyethyl) furan-2,5-dicarboxylate (BHEF), via crystallization was the slowest step in the overall recycling process. The recovered BHEF was repolymerized into virgin-like higher-performance PEF compared with the original material, demonstrating polymer circularity and a potential for upcycling.