Recycling of Multilayer Flexible Packaging Waste Through Delamination with Recoverable Switchable Hydrophilicity Solvents

Multilayer flexible packaging wastes (MFPWs) consist of complex materials composed of multiple plastic films, which are often laminated with aluminum foil, and they constitute a large portion of packaging waste. The use of several polymeric layers is essential to achieve the desired technical and me...

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Main Authors: Roberta Mastroddi, Chiara Samorì, Martina Vagnoni, Chiara Gualandi, Paola Galletti, Emilio Tagliavini
Format: Article
Language:English
Published: MDPI AG 2025-02-01
Series:Separations
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Online Access:https://www.mdpi.com/2297-8739/12/2/45
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author Roberta Mastroddi
Chiara Samorì
Martina Vagnoni
Chiara Gualandi
Paola Galletti
Emilio Tagliavini
author_facet Roberta Mastroddi
Chiara Samorì
Martina Vagnoni
Chiara Gualandi
Paola Galletti
Emilio Tagliavini
author_sort Roberta Mastroddi
collection DOAJ
description Multilayer flexible packaging wastes (MFPWs) consist of complex materials composed of multiple plastic films, which are often laminated with aluminum foil, and they constitute a large portion of packaging waste. The use of several polymeric layers is essential to achieve the desired technical and mechanical performance of the packaging; however, this makes layer separation and recycling challenging. Currently, this type of waste is predominantly incinerated or landfilled; non-industrial recycling processes have recently been developed, but they mostly rely on traditional solvent-based treatments, which can be problematic. We present a versatile process for recycling MFPWs using switchable hydrophilicity solvents (SHSs). By treating waste with SHSs through a temperature-controlled process, we efficiently recovered the polymeric layers as sorted transparent films, effectively removing all additives while preserving the original properties of the polymers. Aluminum was recovered as well. <i>N</i>,<i>N</i>-dimethylcyclohexylamine was the best solvent for the delamination of the 26 different packaging materials tested, containing polypropylene, polyethylene, polyethylene terephthalate, and aluminum. The main advantage of this method is the straightforward recovery of the different components that can be efficiently delaminated and easily removed from the solvent, even from highly variable input material. Moreover, by exploiting the CO<sub>2</sub>-triggered switchable behavior of the solvent, its purification and recovery can be achieved, maintaining its delamination efficacy over several cycles.
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spelling doaj-art-997f23f6c019455ca42d6f2b5ed312d92025-08-20T02:44:43ZengMDPI AGSeparations2297-87392025-02-011224510.3390/separations12020045Recycling of Multilayer Flexible Packaging Waste Through Delamination with Recoverable Switchable Hydrophilicity SolventsRoberta Mastroddi0Chiara Samorì1Martina Vagnoni2Chiara Gualandi3Paola Galletti4Emilio Tagliavini5Dipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum—Università di Bologna, Via P. Gobetti 85, 40129 Bologna, ItalyDipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum—Università di Bologna, Via P. Gobetti 85, 40129 Bologna, ItalyDipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum—Università di Bologna, Via P. Gobetti 85, 40129 Bologna, ItalyDipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum—Università di Bologna, Via P. Gobetti 85, 40129 Bologna, ItalyDipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum—Università di Bologna, Via P. Gobetti 85, 40129 Bologna, ItalyDipartimento di Chimica “Giacomo Ciamician”, Alma Mater Studiorum—Università di Bologna, Via P. Gobetti 85, 40129 Bologna, ItalyMultilayer flexible packaging wastes (MFPWs) consist of complex materials composed of multiple plastic films, which are often laminated with aluminum foil, and they constitute a large portion of packaging waste. The use of several polymeric layers is essential to achieve the desired technical and mechanical performance of the packaging; however, this makes layer separation and recycling challenging. Currently, this type of waste is predominantly incinerated or landfilled; non-industrial recycling processes have recently been developed, but they mostly rely on traditional solvent-based treatments, which can be problematic. We present a versatile process for recycling MFPWs using switchable hydrophilicity solvents (SHSs). By treating waste with SHSs through a temperature-controlled process, we efficiently recovered the polymeric layers as sorted transparent films, effectively removing all additives while preserving the original properties of the polymers. Aluminum was recovered as well. <i>N</i>,<i>N</i>-dimethylcyclohexylamine was the best solvent for the delamination of the 26 different packaging materials tested, containing polypropylene, polyethylene, polyethylene terephthalate, and aluminum. The main advantage of this method is the straightforward recovery of the different components that can be efficiently delaminated and easily removed from the solvent, even from highly variable input material. Moreover, by exploiting the CO<sub>2</sub>-triggered switchable behavior of the solvent, its purification and recovery can be achieved, maintaining its delamination efficacy over several cycles.https://www.mdpi.com/2297-8739/12/2/45switchable solventsdelaminationmultilayer flexible packaging wasterecyclingCO<sub>2</sub>
spellingShingle Roberta Mastroddi
Chiara Samorì
Martina Vagnoni
Chiara Gualandi
Paola Galletti
Emilio Tagliavini
Recycling of Multilayer Flexible Packaging Waste Through Delamination with Recoverable Switchable Hydrophilicity Solvents
Separations
switchable solvents
delamination
multilayer flexible packaging waste
recycling
CO<sub>2</sub>
title Recycling of Multilayer Flexible Packaging Waste Through Delamination with Recoverable Switchable Hydrophilicity Solvents
title_full Recycling of Multilayer Flexible Packaging Waste Through Delamination with Recoverable Switchable Hydrophilicity Solvents
title_fullStr Recycling of Multilayer Flexible Packaging Waste Through Delamination with Recoverable Switchable Hydrophilicity Solvents
title_full_unstemmed Recycling of Multilayer Flexible Packaging Waste Through Delamination with Recoverable Switchable Hydrophilicity Solvents
title_short Recycling of Multilayer Flexible Packaging Waste Through Delamination with Recoverable Switchable Hydrophilicity Solvents
title_sort recycling of multilayer flexible packaging waste through delamination with recoverable switchable hydrophilicity solvents
topic switchable solvents
delamination
multilayer flexible packaging waste
recycling
CO<sub>2</sub>
url https://www.mdpi.com/2297-8739/12/2/45
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