Catalytic Fabric Recycling: Glycolysis of Blended PET with Carbon Dioxide and Ammonia

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The ubiquity of nonbiodegradable polyethylene terephthalate (PET) materials has led to significant waste management challenges. Although PET plastics can be recycled, blended materials, such as PET/cotton fabrics, complicate the recycling process due to the labile glycosidic bonds in cotton. In this study, we present a practical and scalable approach for recycling of PET and PET/cotton interwoven fabrics via catalytic glycolysis with ammonium bicarbonate (NH4HCO3), which decomposed to ammonia, carbon dioxide, and water. This catalytic approach outperformed conventional acid/base and metal catalysis in selectively recovering and upcycling cotton-based materials. We demonstrated the large-scale recovery of textile from blended fabrics (up to 213 g), showcasing the advantages of traceless catalysis using ammonia and CO2 from ammonium bicarbonate. Owing to our metal-free reaction conditions, high-purity bis(hydroxyethyl)terephthalate (BHET) was obtained which was thermally repolymerized to PET. Through thermal analysis, kinetics, and control experiments, we show that ammonia and CO2 are crucial for achieving optimal glycolysis via transesterification. Our method offered a traceless, environmentally friendly, and practical approach for polyester recycling and cotton recovery, representing a significant step toward sustainable, closed-loop production of plastics and textiles.

Original languageEnglish
JournalACS Sustainable Chemistry and Engineering
Volume11
Issue number30
Pages (from-to)11294-11304
Number of pages11
ISSN2168-0485
DOIs
Publication statusPublished - 2023

Bibliographical note

Funding Information:
This paper is dedicated to the Department of Chemistry, Sungkyunkwan University, on the occasion of its 70th anniversary. The generous support from the Department of Chemistry, University of Copenhagen, the Carlsberg Foundation (CF21-0308), NNF CO Research Center (CORC), and the Novo Nordisk Foundation (NNF20OC0064347) is gratefully acknowledged. We thank Prof. Troels Skrydstrup for the fruitful discussion on depolymerization and Dr. Theis Brock-Nannestad, Christian Tortzen, and Prof. Pernille Harris for the analysis and acquisition of optical microscope images. The NMR Center • DTU and the Villum Foundation are acknowledged for allowing us access to the 600 MHz spectrometer. We acknowledge Prof. Heloisa Nunes Bordallo and CPHarma, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, for the access to TGA and DSC measurements. We also thank our analytical departments for their kind support. 2

Funding Information:
This paper is dedicated to the Department of Chemistry, Sungkyunkwan University, on the occasion of its 70th anniversary. The generous support from the Department of Chemistry, University of Copenhagen, the Carlsberg Foundation (CF21-0308), NNF CO2 Research Center (CORC), and the Novo Nordisk Foundation (NNF20OC0064347) is gratefully acknowledged. We thank Prof. Troels Skrydstrup for the fruitful discussion on depolymerization and Dr. Theis Brock-Nannestad, Christian Tortzen, and Prof. Pernille Harris for the analysis and acquisition of optical microscope images. The NMR Center • DTU and the Villum Foundation are acknowledged for allowing us access to the 600 MHz spectrometer. We acknowledge Prof. Heloisa Nunes Bordallo and CPHarma, Department of Pharmacy, Faculty of Health and Medical Sciences, University of Copenhagen, for the access to TGA and DSC measurements. We also thank our analytical departments for their kind support.

Publisher Copyright:
© 2023 American Chemical Society.

    Research areas

  • carbon dioxide, fabric, glycolysis, plastic, polyethylene terephthalates

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