{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,7]],"date-time":"2026-02-07T09:38:04Z","timestamp":1770457084866,"version":"3.49.0"},"reference-count":45,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2021,5,28]],"date-time":"2021-05-28T00:00:00Z","timestamp":1622160000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100008530","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["POCI-01-0145-FEDER-029742 (POLYCEL)"],"award-info":[{"award-number":["POCI-01-0145-FEDER-029742 (POLYCEL)"]}],"id":[{"id":"10.13039\/501100008530","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100011929","name":"COMPETE","doi-asserted-by":"publisher","award":["UIDB\/00285\/2020 and UIBD\/00511\/2020."],"award-info":[{"award-number":["UIDB\/00285\/2020 and UIBD\/00511\/2020."]}],"id":[{"id":"10.13039\/501100011929","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Due to environmental concerns, more attention has been given to the development of bio-based materials for substitution of fossil-based ones. Moreover, paper use is essential in daily routine and several applications of industrial pulp can be developed. In this study, transparent films were produced by industrial cellulose pulp solubilization in tetramethylguanidine based ionic liquids followed by its regeneration. Films were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), UV\/Vis spectroscopy, proton nuclear magnetic resonance (1H-NMR), dynamic scanning calorimetry (DSC), thermal analysis (TG), and X-ray diffraction (XRD). Mechanical tests showed that films have a good elongation property, up to 50%, depending on ionic liquid incorporation. The influence of the conjugated acid and dissolution temperature on mechanical properties were evaluated. These results revealed the potential of this methodology for the preparation of new biobased films.<\/jats:p>","DOI":"10.3390\/polym13111767","type":"journal-article","created":{"date-parts":[[2021,5,31]],"date-time":"2021-05-31T03:45:29Z","timestamp":1622432729000},"page":"1767","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":21,"title":["Process Development for Flexible Films of Industrial Cellulose Pulp Using Superbase Ionic Liquids"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7342-7799","authenticated-orcid":false,"given":"Diana C. M.","family":"Ribeiro","sequence":"first","affiliation":[{"name":"Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), Department of Chemical Engineering, University of Coimbra, Rua S\u00edlvio Lima-Polo II, 3030-790 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0317-9504","authenticated-orcid":false,"given":"Rafael C.","family":"Rebelo","sequence":"additional","affiliation":[{"name":"Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), Department of Chemical Engineering, University of Coimbra, Rua S\u00edlvio Lima-Polo II, 3030-790 Coimbra, Portugal"}]},{"given":"Francesco","family":"De Bon","sequence":"additional","affiliation":[{"name":"Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), Department of Chemical Engineering, University of Coimbra, Rua S\u00edlvio Lima-Polo II, 3030-790 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9351-1704","authenticated-orcid":false,"given":"Jorge F. J.","family":"Coelho","sequence":"additional","affiliation":[{"name":"Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), Department of Chemical Engineering, University of Coimbra, Rua S\u00edlvio Lima-Polo II, 3030-790 Coimbra, Portugal"}]},{"given":"Arm\u00e9nio C.","family":"Serra","sequence":"additional","affiliation":[{"name":"Centre for Mechanical Engineering, Materials and Processes (CEMMPRE), Department of Chemical Engineering, University of Coimbra, Rua S\u00edlvio Lima-Polo II, 3030-790 Coimbra, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2021,5,28]]},"reference":[{"key":"ref_1","unstructured":"Gourmelon, G. (2015). Global Plastic Production Rises, Recycling Lags, Worldwatch Institute. Available online: http:\/\/www.plastic-resource-center.com."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.mser.2018.01.002","article-title":"Naturally-derived biopolymer nanocomposites: Interfacial design, properties and emerging applications","volume":"125","author":"Xiong","year":"2018","journal-title":"Mater. Sci. Eng. R Rep."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"3358","DOI":"10.1002\/anie.200460587","article-title":"Cellulose: Fascinating Biopolymer and Sustainable Raw Material","volume":"44","author":"Klemm","year":"2005","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Kostag, M., Jedvert, K., Achtel, C., Heinze, T., and El Seoud, O.A. (2018). Recent Advances in Solvents for the Dissolution, Shaping and Derivatization of Cellulose: Quaternary Ammonium Electrolytes and their Solutions in Water and Molecular Solvents. Molecules, 23.","DOI":"10.3390\/molecules23030511"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"109","DOI":"10.1016\/j.biortech.2013.12.040","article-title":"A process for enhancing the accessibility and reactivity of hardwood kraft-based dissolving pulp for viscose rayon production by cellulase treatment","volume":"154","author":"Miao","year":"2014","journal-title":"Bioresour. Technol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"267","DOI":"10.1016\/S0144-8617(97)00101-X","article-title":"Theory and applications of DMAC\/LICL in the analysis of polysaccharides","volume":"34","author":"Striegel","year":"1997","journal-title":"Carbohydr. Polym."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1002\/mabi.200400222","article-title":"Rapid Dissolution of Cellulose in LiOH\/Urea and NaOH\/Urea Aqueous Solutions","volume":"5","author":"Cai","year":"2005","journal-title":"Macromol. Biosci."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"6153","DOI":"10.1016\/S0032-3861(03)00663-3","article-title":"On the conformation of the cellulose solvent N-methylmorpholine-N-oxide (NMMO) in solution","volume":"44","author":"Rosenau","year":"2003","journal-title":"Polymer"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"4974","DOI":"10.1021\/ja025790m","article-title":"Dissolution of Cellose with Ionic Liquids","volume":"124","author":"Swatloski","year":"2002","journal-title":"J. Am. Chem. Soc."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"100162","DOI":"10.1016\/j.scp.2019.100162","article-title":"Dissolution of cellulose in ionic liquids and their mixed cosolvents: A review","volume":"13","author":"Verma","year":"2019","journal-title":"Sustain. Chem. Pharm."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"115058","DOI":"10.1016\/j.carbpol.2019.115058","article-title":"Ionic liquid induces flexibility and thermoplasticity in cellulose film","volume":"223","author":"Haq","year":"2019","journal-title":"Carbohydr. Polym."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1039\/b110838g","article-title":"A short history of ionic liquids\u2014from molten salts to neoteric solvents","volume":"4","author":"Wilkes","year":"2002","journal-title":"Green Chem."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1994","DOI":"10.1134\/S1070363212120158","article-title":"Synthesis and dissolving power of 1-Alkyl-3-methylpyridinium-based ionic liquids","volume":"82","author":"Sashina","year":"2012","journal-title":"Russ. J. Gen. Chem."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1273","DOI":"10.1039\/C6QM00348F","article-title":"Application of ionic liquids for dissolving cellulose and fabricating cellulose-based materials: State of the art and future trends","volume":"1","author":"Zhang","year":"2017","journal-title":"Mater. Chem. Front."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"46925","DOI":"10.1002\/app.46925","article-title":"All-cellulose films with excellent strength and toughness via a facile approach of dissolution-regeneration","volume":"136","author":"Cheng","year":"2019","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"45488","DOI":"10.1002\/app.45488","article-title":"Preparations, properties, and formation mechanism of novel cellulose hydrogel membrane based on ionic liquid","volume":"135","author":"Peng","year":"2017","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"9194","DOI":"10.1039\/C5RA23616A","article-title":"Ionic liquids derived from organosuperbases: En route to superionic liquids","volume":"6","author":"Nowicki","year":"2016","journal-title":"RSC Adv."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"6301","DOI":"10.1002\/anie.201100274","article-title":"Distillable Acid-Base Conjugate Ionic Liquids for Cellulose Dissolution and Processing","volume":"50","author":"King","year":"2011","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2161","DOI":"10.1002\/cssc.201300143","article-title":"Predicting Cellulose Solvating Capabilities of Acid-Base Conjugate Ionic Liquids","volume":"6","author":"Parviainen","year":"2013","journal-title":"ChemSusChem"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"115594","DOI":"10.1016\/j.carbpol.2019.115594","article-title":"Highly efficient cellulose dissolution by alkaline ionic liquids","volume":"229","author":"Lethesh","year":"2020","journal-title":"Carbohydr. Polym."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"El Seoud, O.A., Kostag, M., Jedvert, K., and Malek, N.I. (2019). Cellulose in Ionic Liquids and Alkaline Solutions: Advances in the Mechanisms of Biopolymer Dissolution and Regeneration. Polymers, 11.","DOI":"10.3390\/polym11121917"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"511","DOI":"10.1039\/C0CC02421J","article-title":"Instantaneous dissolution of cellulose in organic electrolyte solutions","volume":"47","author":"Rinaldi","year":"2011","journal-title":"Chem. Commun."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"20001","DOI":"10.1039\/c3ra42987c","article-title":"Cellulose hydrolysis with thermo- and alkali-tolerant cellulases in cellulose-dissolving superbase ionic liquids","volume":"3","author":"King","year":"2013","journal-title":"RSC Adv."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"786","DOI":"10.1177\/004051755902901003","article-title":"An Empirical Method for Estimating the Degree of Crystallinity of Native Cellulose Using the X-Ray Diffractometer","volume":"29","author":"Segal","year":"1959","journal-title":"Text. Res. J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"582","DOI":"10.1016\/j.molliq.2016.05.008","article-title":"Cellulose dissolution and regeneration using various imidazolium based protic ionic liquids","volume":"238","author":"Meenatchi","year":"2017","journal-title":"J. Mol. Liq."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"8020","DOI":"10.1039\/c2ra21287k","article-title":"Relative and inherent reactivities of imidazolium-based ionic liquids: The implications for lignocellulose processing applications","volume":"2","author":"King","year":"2012","journal-title":"RSC Adv."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.eurpolymj.2019.01.053","article-title":"Dissolution of cellulose in novel carboxylate-based ionic liquids and dimethyl sulfoxide mixed solvents","volume":"113","author":"Kasprzak","year":"2019","journal-title":"Eur. Polym. J."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1000","DOI":"10.1016\/j.matt.2020.01.016","article-title":"Critical Role of Degree of Polymerization of Cellulose in Super-Strong Nanocellulose Films","volume":"2","author":"Fang","year":"2020","journal-title":"Matter"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1270","DOI":"10.3390\/ma6041270","article-title":"Fabrication of Cellulose Film with Enhanced Mechanical Properties in Ionic Liquid 1-Allyl-3-methylimidaxolium Chloride (AmimCl)","volume":"6","author":"Pang","year":"2013","journal-title":"Materals"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"214","DOI":"10.1016\/j.carbpol.2018.09.060","article-title":"Preparation of transparent film via cellulose regeneration: Correlations between ionic liquid and film properties","volume":"203","author":"Zheng","year":"2019","journal-title":"Carbohydr. Polym."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1487","DOI":"10.1039\/C5SM02618K","article-title":"Cellulose regeneration and spinnability from ionic liquids","volume":"12","author":"Hauru","year":"2015","journal-title":"Soft Matter"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"6555","DOI":"10.1016\/j.polymer.2013.10.012","article-title":"Moisture induced plasticity of amorphous cellulose films from ionic liquid","volume":"54","author":"Sundberg","year":"2013","journal-title":"Polymer"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"255","DOI":"10.3176\/proc.2016.3.09","article-title":"Ionic liquids as solvents for making composite materials from cellulose","volume":"65","author":"Elhi","year":"2016","journal-title":"Proc. Estonian Acad. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"387","DOI":"10.1016\/j.carbpol.2018.08.031","article-title":"Effects of temperature on cellulose hydrogen bonds during dissolution in ionic liquid","volume":"201","author":"Wei","year":"2018","journal-title":"Carbohydr. Polym."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1155\/2014\/214057","article-title":"Fabrication and Characterization of Regenerated Cellulose Films Using Different Ionic Liquids","volume":"2014","author":"Pang","year":"2014","journal-title":"J. Spectrosc."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"269","DOI":"10.1002\/pol.1959.1203913521","article-title":"Infrared spectra of crystalline polysaccharides. II. Native celluloses in the region from 640 to 1700 cm.1","volume":"39","author":"Liang","year":"1959","journal-title":"J. Polym. Sci."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1578","DOI":"10.1016\/j.ijbiomac.2020.11.037","article-title":"Natural lignocellulosic nanofibril film with excellent ultraviolet blocking performance and robust environment resistance","volume":"166","author":"Bian","year":"2021","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_38","first-page":"151","article-title":"Speculations on the nature of cellulose pyrolysis","volume":"2","author":"Kilzer","year":"1965","journal-title":"Pyrodinamics"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"175","DOI":"10.1016\/0040-6031(94)02102-T","article-title":"Analysis of different kinetic models in the dynamic pyrolysis of cellulose","volume":"254","author":"Conesa","year":"1995","journal-title":"Thermochim. Acta"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"111","DOI":"10.1016\/S0141-3910(99)00100-7","article-title":"Thermal behavior of cellulose and some cellulose derivatives","volume":"67","author":"Nada","year":"2000","journal-title":"Polym. Degrad. Stab."},{"key":"ref_41","first-page":"445","article-title":"Glass transition temperature and thermal decomposition of cellulose powder","volume":"15","author":"Rachocki","year":"2007","journal-title":"Cellul."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10965-015-0866-4","article-title":"A new understanding concerning the influence of structural changes on the thermal behavior of cellulose","volume":"22","author":"Chen","year":"2015","journal-title":"J. Polym. Res."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"2376","DOI":"10.1016\/j.carres.2005.08.007","article-title":"Crystalline structure analysis of cellulose treated with sodium hydroxide and carbon dioxide by means of X-ray diffraction and FTIR spectroscopy","volume":"340","author":"Oh","year":"2005","journal-title":"Carbohydr. Res."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1007\/s10570-020-03444-8","article-title":"Cellulose dissolution and regeneration using a non-aqueous, non-stoichiometric protic ionic liquid system","volume":"27","author":"Berga","year":"2020","journal-title":"Cellulose"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"99","DOI":"10.1016\/j.carbpol.2014.09.053","article-title":"Preparation and characterization of regenerated cellulose from ionic liquid using different methods","volume":"117","author":"Liu","year":"2015","journal-title":"Carbohydr. Polym."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/13\/11\/1767\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:09:30Z","timestamp":1760162970000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/13\/11\/1767"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,5,28]]},"references-count":45,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2021,6]]}},"alternative-id":["polym13111767"],"URL":"https:\/\/doi.org\/10.3390\/polym13111767","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,28]]}}}