{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T02:34:05Z","timestamp":1774578845177,"version":"3.50.1"},"reference-count":28,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,24]],"date-time":"2025-12-24T00:00:00Z","timestamp":1766534400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>In a quest to develop more sustainable polymers, decoupling their production from fuel-based resources and searching for alternative greener synthetic pathways are important priorities. Among the numerous polymers that fall into this category are furan-based polyesters. Besides the origin of polymers, their synthesis is another critical topic to consider regarding the overall greenness of the final product. However, despite several studies focusing on bio-based alternatives, such as poly(alkylene 2,5-furandicarboxylate)s, their synthesis still relies on air- and water-sensitive metal-based catalysts and is typically carried out under harsh conditions. This study explores an alternative approach with the application of eutectic solvents (ES) as catalysts for a more sustainable approach for synthesising furan-based polyesters, specifically poly(ethylene 2,5-furandicarboxylate) (PEF), as well as poly(trimethylene furandicarboxylate) (PTF) and poly(butylene furandicarboxylate) (PBF). Two different ES were evaluated as catalysts; the best results were obtained with urea and zinc acetate ES (U:Zn(OAc)2, 4:1 mol:mol). The resulting polymers were analysed for their structure, molecular weight, and thermal properties.<\/jats:p>","DOI":"10.3390\/molecules31010077","type":"journal-article","created":{"date-parts":[[2025,12,24]],"date-time":"2025-12-24T14:27:51Z","timestamp":1766586471000},"page":"77","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["The Evaluation of Eutectic Solvents as Catalysts for Mediating the Greener Synthesis of Poly(alkylene 2,5-furandicarboxylate)s"],"prefix":"10.3390","volume":"31","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8885-2704","authenticated-orcid":false,"given":"Beatriz","family":"Agostinho","sequence":"first","affiliation":[{"name":"CICECO\u2014Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8255-9494","authenticated-orcid":false,"given":"Vin\u00edcius","family":"de Paula","sequence":"additional","affiliation":[{"name":"CICECO\u2014Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5403-8416","authenticated-orcid":false,"given":"Armando J. D.","family":"Silvestre","sequence":"additional","affiliation":[{"name":"CICECO\u2014Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3044-3016","authenticated-orcid":false,"given":"Andreia F.","family":"Sousa","sequence":"additional","affiliation":[{"name":"CICECO\u2014Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,24]]},"reference":[{"key":"ref_1","unstructured":"(2024). Plastics Europe Plastics\u2014The Fast Facts 2024, Plastics Europe."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"5961","DOI":"10.1039\/C5PY00686D","article-title":"Biobased Polyesters and Other Polymers from 2,5-Furandicarboxylic Acid: A Tribute to Furan Excellency","volume":"6","author":"Sousa","year":"2015","journal-title":"Polym. Chem."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Loos, K., Zhang, R., Pereira, I., Agostinho, B., Hu, H., Maniar, D., Sbirrazzuoli, N., Silvestre, A.J.D.D., Guigo, N., and Sousa, A.F. (2020). A Perspective on PEF Synthesis, Properties, and End-Life. Front. Chem., 8.","DOI":"10.3389\/fchem.2020.00585"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"8795","DOI":"10.1039\/D1GC02082J","article-title":"Recommendations for Replacing PET on Packaging, Fiber, and Film Materials with Biobased Counterparts","volume":"23","author":"Sousa","year":"2021","journal-title":"Green Chem."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"9558","DOI":"10.1021\/acssuschemeng.0c02840","article-title":"Fully Biobased Superpolymers of 2,5-Furandicarboxylic Acid with Different Functional Properties: From Rigid to Flexible, High Performant Packaging Materials","volume":"8","author":"Guidotti","year":"2020","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_6","unstructured":"(2024, January 08). Avantium YXY\u00ae Technology. Available online: https:\/\/www.avantium.com\/technologies\/yxy\/."},{"key":"ref_7","unstructured":"(2025, December 11). Avantium Avantium and Carlsberg Sign Offtake Agreement on PEF. Available online: https:\/\/newsroom.avantium.com\/avantium-and-carlsberg-sign-offtake-agreement-on-pef\/."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1026","DOI":"10.1002\/pola.25859","article-title":"A Series of Furan-Aromatic Polyesters Synthesized via Direct Esterification Method Based on Renewable Resources","volume":"50","author":"Jiang","year":"2012","journal-title":"J. Polym. Sci. Part A Polym. Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1002\/pola.23130","article-title":"The Furan Counterpart of Poly(Ethylene Terephthalate): An Alternative Material Based on Renewable Resources","volume":"47","author":"Gandini","year":"2009","journal-title":"J. Polym. Sci. Part A Polym. Chem."},{"key":"ref_10","unstructured":"(2025, March 11). PubChem Antimony Trioxide, Available online: https:\/\/pubchem.ncbi.nlm.nih.gov\/compound\/Antimony-trioxide."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"101578","DOI":"10.1039\/C6RA21135F","article-title":"DBU-Catalyzed Biobased Poly(Ethylene 2,5-Furandicarboxylate) Polyester with Rapid Melt Crystallization: Synthesis, Crystallization Kinetics and Melting Behavior","volume":"6","author":"Wu","year":"2016","journal-title":"RSC Adv."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"4927","DOI":"10.1002\/cssc.201902020","article-title":"A Br\u00f8nsted Acidic Ionic Liquid as an Efficient and Selective Catalyst System for Bioderived High Molecular Weight Poly(Ethylene 2,5-Furandicarboxylate)","volume":"12","author":"Qu","year":"2019","journal-title":"ChemSusChem"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"8497","DOI":"10.1039\/D4GC00532E","article-title":"Deep Eutectic Solvents towards Green Polymeric Materials","volume":"26","author":"Weerasinghe","year":"2024","journal-title":"Green Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"48675","DOI":"10.1039\/C5RA05746A","article-title":"Recent Advances in the Application of Deep Eutectic Solvents as Sustainable Media as Well as Catalysts in Organic Reactions","volume":"5","author":"Liu","year":"2015","journal-title":"RSC Adv."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"141","DOI":"10.1146\/annurev-chembioeng-101121-085323","article-title":"Everything You Wanted to Know about Deep Eutectic Solvents but Were Afraid to Be Told","volume":"14","author":"Abranches","year":"2023","journal-title":"Annu. Rev. Chem. Biomol. Eng."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"962","DOI":"10.1007\/s10953-018-0793-1","article-title":"Insights into the Nature of Eutectic and Deep Eutectic Mixtures","volume":"48","author":"Martins","year":"2019","journal-title":"J. Solution Chem."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"943","DOI":"10.1016\/j.tibtech.2019.03.007","article-title":"Deep Eutectic Solvents as Efficient Solvents in Biocatalysis","volume":"37","author":"Siebenhaller","year":"2019","journal-title":"Trends Biotechnol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1021\/bk-2020-1373.ch001","article-title":"Green Pathways for the Enzymatic Synthesis of Furan-Based Polyesters and Polyamides","volume":"1373","author":"Silvianti","year":"2020","journal-title":"ACS Symp. Ser."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"82","DOI":"10.1021\/acspolymersau.2c00035","article-title":"Greener Synthesis Route for Furanic-Aliphatic Polyester: Enzymatic Polymerization in Ionic Liquids and Deep Eutectic Solvents","volume":"3","author":"Silvianti","year":"2023","journal-title":"ACS Polym. Au"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3577","DOI":"10.1021\/acssuschemeng.4c09545","article-title":"Closing the Loop: Greener and Efficient Hydrolytic Depolymerization for the Recycling of Polyesters Using Biobased Eutectic Solvents","volume":"13","author":"Pandeirada","year":"2025","journal-title":"ACS Sustain. Chem. Eng."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2473","DOI":"10.1039\/C4GC02401J","article-title":"Deep Eutectic Solvents as Highly Active Catalysts for the Fast and Mild Glycolysis of Poly(Ethylene Terephthalate)(PET)","volume":"17","author":"Wang","year":"2015","journal-title":"Green Chem."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Paparella, A.N., Perrone, S., Salomone, A., Messa, F., Cicco, L., Capriati, V., Perna, F.M., and Vitale, P. (2023). Use of Deep Eutectic Solvents in Plastic Depolymerization. Catalysts, 13.","DOI":"10.3390\/catal13071035"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3115","DOI":"10.1039\/D2GC00074A","article-title":"From PEF to RPEF: Disclosing the Potential of Deep Eutectic Solvents in Continuous de-\/Re-Polymerization Recycling of Biobased Polyesters","volume":"24","author":"Agostinho","year":"2022","journal-title":"Green Chem."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"794","DOI":"10.1016\/j.molliq.2018.12.032","article-title":"Physical Properties of Ethylene Glycol-Based Deep Eutectic Solvents","volume":"276","author":"Ibrahim","year":"2019","journal-title":"J. Mol. Liq."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"1098","DOI":"10.1021\/ed100461v","article-title":"Polymer Molecular Weight Analysis by 1H NMR Spectroscopy","volume":"88","author":"Izunobi","year":"2011","journal-title":"J. Chem. Educ."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1536","DOI":"10.1002\/pen.25675","article-title":"The Effect of Annealing on Tensile Properties of Injection Molded Biopolyesters Based on 2,5-Furandicarboxylic Acid","volume":"61","author":"Zubkiewicz","year":"2021","journal-title":"Polym. Eng. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"5324","DOI":"10.1039\/C9PY00844F","article-title":"Highly Transparent Films of New Copolyesters Derived from Terephthalic and 2,4-Furandicarboxylic Acids","volume":"10","author":"Zaidi","year":"2019","journal-title":"Polym. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Matos, M., Sousa, A.F., Silva, N.H.C.S., Freire, C.S.R., Andrade, M., Mendes, A., and Silvestre, A.J.D. (2018). Furanoate-Based Nanocomposites: A Case Study Using Poly(Butylene 2,5-Furanoate) and Poly(Butylene 2,5-Furanoate)-Co-(Butylene Diglycolate) and Bacterial Cellulose. Polymers, 10.","DOI":"10.3390\/polym10080810"}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/1\/77\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,26]],"date-time":"2025-12-26T05:27:22Z","timestamp":1766726842000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/1\/77"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,12,24]]},"references-count":28,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2026,1]]}},"alternative-id":["molecules31010077"],"URL":"https:\/\/doi.org\/10.3390\/molecules31010077","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,12,24]]}}}