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Li T, Theodosopoulos G, Lovell C, Loukodimou A, Maniam KK, Paul S. Progress in Solvent-Based Recycling of Polymers from Multilayer Packaging. Polymers (Basel) 2024; 16:1670. [PMID: 38932020 PMCID: PMC11207984 DOI: 10.3390/polym16121670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 06/03/2024] [Accepted: 06/06/2024] [Indexed: 06/28/2024] Open
Abstract
Conversion of chemical feedstocks derived from fossil fuels to virgin polymer, manufacturing of plastics in coal-dependent economies, and increasing consumption of virgin polymers for plastics packaging contribute significantly to environmental issues and the challenges we face. Nowadays, promoting sustainable development has become the consensus of more and more countries. Among them, the recycling of multilayer packaging is a huge challenge. Due to the complexity of its structure and materials, as well as the limitations of existing recycling frameworks, currently, multilayer packaging cannot be commercially recycled thus resulting in a series of circular economy challenges. It is undeniable that multilayer packaging offers many positive effects on products and consumers, so banning the use of such packaging would be unwise and unrealistic. Developing the appropriate processes to recycle multilayer packaging is the most feasible strategy. In recent years, there have been some studies devoted to the recycling process of multilayer packaging. Many of the processes being developed involve the use of solvents. Based on the recycled products, we categorised these recycling processes as solvent-based recycling, including physical dissolution and chemical depolymerisation. In physical dissolution, there are mainly two approaches named delamination and selective dissolution-precipitation. Focusing on these processes, this paper reviews the solvents developed and used in the last 20 years for the recycling of polymers from multilayer packaging waste and gives a summary of their advantages and disadvantages in terms of cost, product quality, ease of processing, and environmental impact. Based on existing research, one could conclude that solvent-based recycling methods have the potential to be commercialised and become part of a standard recycling process for polymer-based multilayer packaging. The combined use of multiple solvent-based recycling processes could be a breakthrough in achieving unified recycling of multilayer packaging with different components.
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Affiliation(s)
- Tianmiao Li
- Materials Innovation Centre, School of Engineering, University of Leicester, Leicester LE1 7RH, UK; (T.L.); (A.L.)
| | - George Theodosopoulos
- Materials Performance and Integrity Technology Group, TWI Ltd., Cambridge CB21 6AL, UK; (G.T.); (K.K.M.)
| | - Chris Lovell
- Materials Performance and Integrity Technology Group, TWI Technology and Training Centre-North East, Middlesbrough TS2 1DJ, UK;
| | - Adamantini Loukodimou
- Materials Innovation Centre, School of Engineering, University of Leicester, Leicester LE1 7RH, UK; (T.L.); (A.L.)
| | - Kranthi Kumar Maniam
- Materials Performance and Integrity Technology Group, TWI Ltd., Cambridge CB21 6AL, UK; (G.T.); (K.K.M.)
| | - Shiladitya Paul
- Materials Innovation Centre, School of Engineering, University of Leicester, Leicester LE1 7RH, UK; (T.L.); (A.L.)
- Materials Performance and Integrity Technology Group, TWI Ltd., Cambridge CB21 6AL, UK; (G.T.); (K.K.M.)
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Carbonell-Blasco MP, Moyano MA, Hernández-Fernández C, Sierra-Molero FJ, Pastor IM, Alonso DA, Arán-Aís F, Orgilés-Calpena E. Polyurethane Adhesives with Chemically Debondable Properties via Diels-Alder Bonds. Polymers (Basel) 2023; 16:21. [PMID: 38201686 PMCID: PMC10780649 DOI: 10.3390/polym16010021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 12/12/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
Covalent adaptable networks (CANs) represent a pioneering advance in polymer science, offering unprecedented versatility in materials design. Unlike conventional adhesives with irreversible bonds, CAN-based polyurethane adhesives have the unique ability to undergo chemical restructuring through reversible bonds. One of the strategies for incorporating these types of reactions in polyurethanes is by functionalisation with Diels-Alder (DA) adducts. By taking advantage of the reversible nature of the DA chemistry, the adhesive undergoes controlled crosslinking and decrosslinking processes, allowing for precise modulation of bond strength. This adaptability is critical in applications requiring reworkability or recyclability, as it allows for easy disassembly and reassembly of bonded components without compromising the integrity of the material. This study focuses on the sustainable synthesis and characterisation of a solvent-based polyurethane adhesive, obtained by functionalising a polyurethane prepolymer with DA diene and dienophiles. The characterisation of the adhesives was carried out using different experimental techniques: nuclear magnetic resonance spectroscopy (NMR), Brookfield viscosity, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and T-peel strength testing of leather/adhesive/rubber joints to determine the adhesive properties, both before and after the application of external stimuli. The conversion of both the DA and retro-Diels-Alder (r-DA) reactions was confirmed by 1H-NMR. The adhesive properties were not altered by the functionalisation of the adhesive prepolymer, showing similar thermal resistance and good rheological and adhesive properties, even exceeding the most demanding technical requirements for upper-to-sole joints in footwear. After the application of an external thermal stimuli, the bonded materials separated without difficulty and without damage, thus facilitating their separation, recovery and recycling.
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Affiliation(s)
- María Pilar Carbonell-Blasco
- Footwear Technology Centre, Campo Alto Campo, Elda, 03600 Alicante, Spain; (M.A.M.); (C.H.-F.); (F.A.-A.); (E.O.-C.)
| | - María Alejandra Moyano
- Footwear Technology Centre, Campo Alto Campo, Elda, 03600 Alicante, Spain; (M.A.M.); (C.H.-F.); (F.A.-A.); (E.O.-C.)
| | - Carlota Hernández-Fernández
- Footwear Technology Centre, Campo Alto Campo, Elda, 03600 Alicante, Spain; (M.A.M.); (C.H.-F.); (F.A.-A.); (E.O.-C.)
| | - Francisco J. Sierra-Molero
- Department of Organic Chemistry, Institute of Organic Synthesis (ISO), Faculty of Sciences, University of Alicante, P.O. Box 99, 03080 Alicante, Spain; (F.J.S.-M.); (I.M.P.); (D.A.A.)
| | - Isidro M. Pastor
- Department of Organic Chemistry, Institute of Organic Synthesis (ISO), Faculty of Sciences, University of Alicante, P.O. Box 99, 03080 Alicante, Spain; (F.J.S.-M.); (I.M.P.); (D.A.A.)
| | - Diego A. Alonso
- Department of Organic Chemistry, Institute of Organic Synthesis (ISO), Faculty of Sciences, University of Alicante, P.O. Box 99, 03080 Alicante, Spain; (F.J.S.-M.); (I.M.P.); (D.A.A.)
| | - Francisca Arán-Aís
- Footwear Technology Centre, Campo Alto Campo, Elda, 03600 Alicante, Spain; (M.A.M.); (C.H.-F.); (F.A.-A.); (E.O.-C.)
| | - Elena Orgilés-Calpena
- Footwear Technology Centre, Campo Alto Campo, Elda, 03600 Alicante, Spain; (M.A.M.); (C.H.-F.); (F.A.-A.); (E.O.-C.)
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3
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von Vacano B, Mangold H, Vandermeulen GWM, Battagliarin G, Hofmann M, Bean J, Künkel A. Sustainable Design of Structural and Functional Polymers for a Circular Economy. Angew Chem Int Ed Engl 2023; 62:e202210823. [PMID: 36197763 DOI: 10.1002/anie.202210823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 10/04/2022] [Accepted: 10/05/2022] [Indexed: 11/06/2022]
Abstract
To achieve a sustainable circular economy, polymer production must start transitioning to recycled and biobased feedstock and accomplish CO2 emission neutrality. This is not only true for structural polymers, such as in packaging or engineering applications, but also for functional polymers in liquid formulations, such as adhesives, lubricants, thickeners or dispersants. At their end of life, polymers must be either collected and recycled via a technical pathway, or be biodegradable if they are not collectable. Advances in polymer chemistry and applications, aided by computational material science, open the way to addressing these issues comprehensively by designing for recyclability and biodegradability. This Review explores how scientific progress, together with emerging regulatory frameworks, societal expectations and economic boundary conditions, paint pathways for the transformation towards a circular economy of polymers.
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Affiliation(s)
| | - Hannah Mangold
- Group Research, BASF SE, 67056, Ludwigshafen am Rhein, Germany
| | - Guido W M Vandermeulen
- Functional Polymers R&D, Care Chemicals Division, BASF SE, 67056, Ludwigshafen am Rhein, Germany
| | | | | | - Jessica Bean
- Group Research, BASF SE, 67056, Ludwigshafen am Rhein, Germany
| | - Andreas Künkel
- Group Research, BASF SE, 67056, Ludwigshafen am Rhein, Germany
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dos Santos JWS, Garcia VADS, Venturini AC, de Carvalho RA, da Silva CF, Yoshida CMP. Sustainable Coating Paperboard Packaging Material Based on Chitosan, Palmitic Acid, and Activated Carbon: Water Vapor and Fat Barrier Performance. Foods 2022; 11:foods11244037. [PMID: 36553777 PMCID: PMC9778014 DOI: 10.3390/foods11244037] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/09/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022] Open
Abstract
Synthetic polymer coatings impact the biodegradable behavior of cellulosic packaging material. The environmental consequences of food packaging disposal have increased consumer concern. The present study aimed to use natural polymer coatings incorporating palmitic acid and activated carbon applied to paperboard surfaces as a sustainable alternative to improve cellulosic packaging material's moisture and fat barrier properties, minimizing the environmental impact. The coating formulation was defined using a Factorial Experimental Design with independent variables: chitosan, palmitic acid, activated carbon concentrations, and the number of coating layers. The highest concentration of chitosan (2.0% w/w) filled the pores of the cellulosic paperboard network, supporting the compounds incorporated into the filmogenic matrix and improving the fat resistance. The water vapor permeability of the coated paperboard material (range: 101 ± 43 to 221 ± 13 g·d-1·m-2) was influenced by the hydrophobicity effect of palmitic acid, the non-polar characteristic of activated carbon, and the number of applied layers. The coating formulation selected was a chitosan concentration of 2.0% (w/w), a palmitic acid concentration of 1.8% (w/w), an activated carbon concentration of 1.2% (w/w), and an application of three layers. The coating provides the potential for a paperboard surface application, improving the cellulosic packaging material's fat and moisture barrier properties and maintaining biodegradability and recyclability.
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Affiliation(s)
| | | | - Anna Cecilia Venturini
- Institute of Ambiental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, Diadema 09913-030, Brazil
| | - Rosemary Aparecida de Carvalho
- Faculty of Animal Science and Food Engineering, University of São Paulo, Pirassununga 13630-000, Brazil
- Correspondence: ; Tel.: +55-11-3565-4355
| | - Classius Ferreira da Silva
- Institute of Ambiental, Chemical and Pharmaceutical Sciences, Federal University of São Paulo, Diadema 09913-030, Brazil
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Buryakovskaya OA, Vlaskin MS. Hydrogen Recovery from Waste Aluminum-Plastic Composites Treated with Alkaline Solution. MATERIALS (BASEL, SWITZERLAND) 2022; 15:8699. [PMID: 36500195 PMCID: PMC9736470 DOI: 10.3390/ma15238699] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/28/2022] [Accepted: 12/03/2022] [Indexed: 06/17/2023]
Abstract
An alternative solution to the problem of aluminum-plastic multilayer waste utilization was suggested. The process can be used for hydrogen generation and layer separation. Three different sorts of aluminum-plastic sandwich materials were treated with an alkali solution. In the temperature range of 50-70 °C, for tablet blisters of polyvinylchloride and aluminum (14.8 wt.%), the latter thoroughly reacted in 15-30 min. For sheets of paper, polyethylene, and aluminum (20 wt.%), full hydrogen 'recovery' from reacted aluminum component took 3-8 min. From the lids of polyethylene terephthalate, aluminum (60 wt.%), and painted polyethylene with perforations, the aluminum was consumed after 45-105 min. The effect of perforations was the reduction of the process duration from nearly 90 min for the lids with no perforations to nearly 45 min for the perforated ones (at 70 °C). Perforations provided better contact between the aluminum foil, isolated between the plastic layers, and the alkali solution. Hydrogen bubbles originating near those perforations provided foil separation from the upper painted plastic layer by creating gas gaps between them. The remaining components of the composite multilayer materials were separated and ready for further recycling.
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Vega J, Salavagione H, Quiles-Díaz S, Seyler H, Gómez-Fatou M, Flores A. The role of molecular architecture on the viscoelastic properties of thermoreversible polyurethane adhesives. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Quiles-Díaz S, Seyler H, Ellis GJ, Shuttleworth PS, Flores A, Gómez-Fatou MA, Salavagione HJ. Designing New Sustainable Polyurethane Adhesives: Influence of the Nature and Content of Diels-Alder Adducts on Their Thermoreversible Behavior. Polymers (Basel) 2022; 14:polym14163402. [PMID: 36015659 PMCID: PMC9414518 DOI: 10.3390/polym14163402] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/05/2022] [Accepted: 08/10/2022] [Indexed: 11/16/2022] Open
Abstract
With a view to the development of new sustainable and functional adhesives, two Diels-Alder (DA) adducts are incorporated as a third component into the curing process of solvent-based and solvent-free polyurethanes in this study. The influence of the nature and content of the DA molecules on the retro-DA (rDA) reaction and its reversibility and cyclability is investigated. It is demonstrated that the bonding/debonding properties of the adhesives are mainly controlled by the concentration of the DA adducts, with a minimum thermoreversible bond (TB) content required that depends on the system and the total ratio between all the diols in the formulation. For the solvent-based system, rDA/DA reversibility can be repeated up to ~20 times without deterioration, in contrast to the solvent-free system where a gradual loss in the DA network reconstruction efficiency is observed. Despite this limitation, the solvent-free system presents clear advantages from an environmental point of view. The changes observed in the physical properties of these new thermoreversible adhesives are of great relevance for recycling strategies and, in particular, their potential for separating multilayered film packaging materials in order to recycle the individual polymer films involved.
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Schmidt J, Grau L, Auer M, Maletz R, Woidasky J. Multilayer Packaging in a Circular Economy. Polymers (Basel) 2022; 14:polym14091825. [PMID: 35566994 PMCID: PMC9103501 DOI: 10.3390/polym14091825] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 04/23/2022] [Accepted: 04/26/2022] [Indexed: 11/16/2022] Open
Abstract
Sorting multilayer packaging is still a major challenge in the recycling of post-consumer plastic waste. In a 2019 Germany-wide field study with 248 participants, lightweight packaging (LWP) was randomly selected and analyzed by infrared spectrometry to identify multilayer packaging in the LWP stream. Further investigations of the multilayer packaging using infrared spectrometry and microscopy were able to determine specific multilayer characteristics such as typical layer numbers, average layer thicknesses, the polymers of the outer and inner layers, and typical multilayer structures for specific packaged goods. This dataset shows that multilayer packaging is mainly selected according to the task to be fulfilled, with practically no concern for its end-of-life recycling properties. The speed of innovation in recycling processes does not keep up with packaging material innovations.
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Affiliation(s)
- Jannick Schmidt
- Institut für Industrial Ecology, Hochschule Pforzheim, Tiefenbronner Straße 65, 75175 Pforzheim, Germany; (M.A.); (J.W.)
- Correspondence: (J.S.); (L.G.)
| | - Laura Grau
- Institut für Industrial Ecology, Hochschule Pforzheim, Tiefenbronner Straße 65, 75175 Pforzheim, Germany; (M.A.); (J.W.)
- Correspondence: (J.S.); (L.G.)
| | - Maximilian Auer
- Institut für Industrial Ecology, Hochschule Pforzheim, Tiefenbronner Straße 65, 75175 Pforzheim, Germany; (M.A.); (J.W.)
| | - Roman Maletz
- Institute of Waste Management and Circular Economy, Technische Universität Dresden, Pratzschwitzer Straße 15, 01796 Pirna, Germany;
| | - Jörg Woidasky
- Institut für Industrial Ecology, Hochschule Pforzheim, Tiefenbronner Straße 65, 75175 Pforzheim, Germany; (M.A.); (J.W.)
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9
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Mangold H, von Vacano B. The Frontier of Plastics Recycling: Rethinking Waste as a Resource for High‐Value Applications. MACROMOL CHEM PHYS 2022. [DOI: 10.1002/macp.202100488] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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10
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Vazquez YV, Castillo LA, Barbosa SE. Rethinking of toiletries rigid bottles for recycling improvement. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 311:114839. [PMID: 35255326 DOI: 10.1016/j.jenvman.2022.114839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/09/2022] [Accepted: 03/02/2022] [Indexed: 06/14/2023]
Abstract
Rethinking of plastic rigid shampoo bottles based on "Design for the Environment" concepts is proposed. Bottles of most consumed shampoo brands with different capacities were selected. Bottle weight/capacity ratio was assessed and compression mechanical properties were evaluated. Oversizing of bottles and high amounts of material used in caps only for aesthetic purposes was proved. The analysis confirmed the need to change marketing strategies based on aesthetic attractiveness by an ecodesign based on functionality and sustainability aspects. The use of single material for the overall bottle is recommended, and it seems that HDPE is more suitable as it is appropriate to make all bottle parts, is recyclable, and has a low price/performance relationship. From a marketing point of view, a proper ecodesign would lead to a paradigm shift from an aesthetic approach to a sustainable one, in line with the environmental awareness of today's consumer.
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Affiliation(s)
- Yamila V Vazquez
- Planta Piloto de Ingeniería Química, PLAPIQUI (UNS-CONICET), Cno. La Carrindanga km. 7, Bahía Blanca, 8000, Argentina; Departamento de Ingeniería Química, Universidad Nacional del Sur (UNS), Av. Alem 1253, Bahía Blanca, 8000, Argentina.
| | - Luciana A Castillo
- Planta Piloto de Ingeniería Química, PLAPIQUI (UNS-CONICET), Cno. La Carrindanga km. 7, Bahía Blanca, 8000, Argentina; Departamento de Ingeniería Química, Universidad Nacional del Sur (UNS), Av. Alem 1253, Bahía Blanca, 8000, Argentina
| | - Silvia E Barbosa
- Planta Piloto de Ingeniería Química, PLAPIQUI (UNS-CONICET), Cno. La Carrindanga km. 7, Bahía Blanca, 8000, Argentina; Departamento de Ingeniería Química, Universidad Nacional del Sur (UNS), Av. Alem 1253, Bahía Blanca, 8000, Argentina
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Production of a PET//LDPE Laminate Using a Reversibly Crosslinking Packaging Adhesive and Recycling in a Small-Scale Technical Plant. RECYCLING 2021. [DOI: 10.3390/recycling6030047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Multilayer packaging is an important part of the packaging market, but it is not recyclable with conventional methods since it is made of different thermodynamically immiscible materials. In this work, it was shown that it is possible to produce a PET//LDPE laminate in a pilot plant for lamination by using an adhesive consisting of maleimide- and furan-functionalized polyurethane prepolymers that cure through the Diels–Alder reaction. The material could then be delaminated in a small-scale recycling plant using a solvent-based recycling process by partially opening the Diels–Alder adducts through the influence of temperature. The PET and LDPE could be recovered without any adhesive residues before each material was regranulated, and in the case of the PE, a film was produced via cast film extrusion. The obtained PET granulate exhibited a slight, approximately 10%, decrease in molecular weight. However, since small amounts of LDPE could not be separated, compatibilization would still be required here for further use of the material. The obtained LDPE film was characterized by means of infrared spectrometry, differential scanning calorimetry, tensile testing, determination of the melt index, and molecular weight. The film showed lower crosslinking than usual for LDPE recycling and exhibited good mechanical properties. In this work, it was thus shown that upscaling of the laminate production with the modified adhesive and also its recycling at the pilot plant scale is possible and thus could be an actual option for recycling multilayer packaging.
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Affiliation(s)
- Jonathan M. Millican
- Macromolecular Chemistry II, Bavarian Polymer Institute, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
| | - Seema Agarwal
- Macromolecular Chemistry II, Bavarian Polymer Institute, University of Bayreuth, Universitätsstrasse 30, 95440 Bayreuth, Germany
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Recyclable Multilayer Packaging by Means of Thermoreversibly Crosslinking Adhesive in the Context of Food Law. Polymers (Basel) 2020; 12:polym12122988. [PMID: 33333812 PMCID: PMC7765215 DOI: 10.3390/polym12122988] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 12/10/2020] [Accepted: 12/11/2020] [Indexed: 12/19/2022] Open
Abstract
Lacking recyclability of multilayer packaging can be overcome by using a thermoreversible crosslinking adhesive consisting of maleimide- and furan-functionalized polyurethane-(PU-)prepolymers, reacting in a Diels–Alder-reaction. Here, the furan-functionalized PU-prepolymer carries furan-side-chains to avoid the usage of an additional crosslinking agent. Thus, N‑(2‑hydroxyethyl)maleimide and furfurylamine are the only two chemicals contained in the adhesive that are not listed in the appendix of EU Regulation 10/2011. Using migration modelling, it could be shown that, at 23 °C, both chemicals have lag-times of only a few minutes if 45 µm PE is used as a barrier. However, if the residual content is below 30 mg/kg, the legally specified maximum amount of 0.01 mg/kg food is not reached. After determining the diffusion coefficients and the activation energy of diffusion through ethylene-vinyl alcohol copolymer (EVOH), it could be determined that the lag-time of the migrants can be extended to at least 9 years by the use of 3 µm EVOH. From a food law point of view, the use of the described adhesive is possible if the above‑mentioned measures are complied.
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Liu Z, Cheng J, Zhang J. An Efficiently Reworkable Thermosetting Adhesive Based on Photoreversible [4+4] Cycloaddition Reaction of Epoxy‐Based Prepolymer with Four Anthracene End Groups. MACROMOL CHEM PHYS 2020. [DOI: 10.1002/macp.202000298] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Ziyu Liu
- Key Laboratory of Carbon Fiber and Functional Polymers Ministry of Education Beijing University of Chemical Technology Beijing 100029 P. R. China
| | - Jue Cheng
- Key Laboratory of Carbon Fiber and Functional Polymers Ministry of Education Beijing University of Chemical Technology Beijing 100029 P. R. China
| | - Junying Zhang
- Key Laboratory of Carbon Fiber and Functional Polymers Ministry of Education Beijing University of Chemical Technology Beijing 100029 P. R. China
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