1
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Nizioł E, Marszałek-Harych A, Zierkiewicz W, John Ł, Ejfler J. Structural subtleties and catalytic activity of sodium aminophenolate complexes in polylactide degradation: towards sustainable waste management solutions. Dalton Trans 2024. [PMID: 38814146 DOI: 10.1039/d4dt01270d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2024]
Abstract
This study explores the intricate coordination chemistry of sodium aminophenolate species and their significant role in the depolymerization of polylactide (PLA), offering novel insights into catalytic degradation processes. By examining sodium coordination entities, including dimers and larger aggregates such as tetramers, we reveal how structural modifications, particularly the manipulation of steric hindrances, influence the formation and stability of these complexes. The dimers, characterized by a unique four-center core (Na-O-Na-O), serve as a foundational motif, which is further elaborated to obtain complexes with varied coordination environments through strategic ligand design. Our research delves into the lability of the amino arm in these complexes, a critical factor that facilitates the coordination of PLA to the sodium center, thereby initiating the depolymerization process. Moreover, DFT studies have been pivotal in identifying the most energetically favorable structures for catalysis, highlighting a distinct preference for an eight-membered ring motif stabilized by intramolecular hydrogen bonds. This motif not only enhances the catalyst's efficiency but also introduces a novel structural paradigm for sodium-based catalysis in PLA degradation. Experimental validation of the theoretical models was achieved through NMR spectroscopy, which confirmed the formation of the active catalyst forms and monitored the progress of PLA degradation. The study presents a comprehensive analysis of the influence of ligand structure on the catalytic activity, underscoring the importance of the eight-membered ring motif. Furthermore, we demonstrate how varying the steric bulk of substituents on the amino arm affects the catalyst's performance, with benzyl-substituted ligands exhibiting superior activity. Our findings offer a profound understanding of the structural factors governing the catalytic efficiency of sodium aminophenolate complexes in PLA degradation. This research not only advances the field of coordination chemistry but also presents a promising avenue for the development of efficient and environmentally friendly catalysts for polymer degradation.
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Affiliation(s)
- Edyta Nizioł
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland.
| | | | - Wiktor Zierkiewicz
- Faculty of Chemistry, Wrocław University of Science and Technology, 27 Wybrzeże Wyspiańskiego, 50-370 Wrocław, Poland
| | - Łukasz John
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland.
| | - Jolanta Ejfler
- Faculty of Chemistry, University of Wrocław, 14 F. Joliot-Curie, 50-383 Wrocław, Poland.
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2
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Li Y, Wang S, Qian S, Liu Z, Weng Y, Zhang Y. Depolymerization and Re/Upcycling of Biodegradable PLA Plastics. ACS OMEGA 2024; 9:13509-13521. [PMID: 38559974 PMCID: PMC10976375 DOI: 10.1021/acsomega.3c08674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 02/18/2024] [Accepted: 02/23/2024] [Indexed: 04/04/2024]
Abstract
With the escalating utilization of plastic products, global attention has been increasingly drawn to environmental pollution and recycling challenges stemming from plastic waste. Against this backdrop, biodegradable plastics have emerged as viable alternatives owing to their sustainability and capacity for biodegradation. Polylactic acid (PLA) presently commands the largest market share among biodegradable plastics, finding extensive application in products such as thin films, medical materials, and biodegradable straws. However, the widespread adoption of PLA is hindered by challenges such as high cost, low recycling rates, and complete degradation to H2O and CO2 in natural conditions. Therefore, it is imperative and time-sensitive to explore solutions for the depolymerization and re/upcycling of PLA waste plastics. This review comprehensively outlines the current landscape of PLA recycling methods, emphasizing the advantages and significance of chemical re/upcycling. The subsequent exploration encompasses recent breakthroughs and technical obstacles inherent in diverse chemical depolymerization methods. Ultimately, this review accentuates the impediments and forthcoming possibilities in the realm of PLA plastics, emphasizing the pursuit of closed-loop recycling and upcycling.
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Affiliation(s)
- YingChao Li
- College of Chemistry and
Chemical Engineering, Henan Polytechnic
University, Jiaozuo 454000, China
| | - Shuai Wang
- College of Chemistry and
Chemical Engineering, Henan Polytechnic
University, Jiaozuo 454000, China
| | - Song Qian
- College of Chemistry and
Chemical Engineering, Henan Polytechnic
University, Jiaozuo 454000, China
| | - Zhijie Liu
- College of Chemistry and
Chemical Engineering, Henan Polytechnic
University, Jiaozuo 454000, China
| | - Yujing Weng
- College of Chemistry and
Chemical Engineering, Henan Polytechnic
University, Jiaozuo 454000, China
| | - Yulong Zhang
- College of Chemistry and
Chemical Engineering, Henan Polytechnic
University, Jiaozuo 454000, China
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3
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Zhang Q, Hu C, Li PY, Bai FQ, Pang X, Chen X. Solvent-Promoted Catalyst-Free Recycling of Waste Polyester and Polycarbonate Materials. ACS Macro Lett 2024:151-157. [PMID: 38227974 DOI: 10.1021/acsmacrolett.3c00581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2024]
Abstract
Polymeric materials are indispensable in our daily lives. However, the generation of vast amounts of waste polymers poses significant environmental and ecological challenges. Instead of resorting to landfilling or incineration, strategies for polymer recycling offer a promising approach to mitigate environmental pollution. Pioneering studies have demonstrated the alcoholysis of waste polyesters and polycarbonates; however, these processes typically require the use of catalysts. Moreover, the development of strategies for catalyst removal and recycling is crucial, particularly in some industrial applications. In contrast, we present a catalyst-free method for the alcoholysis of common polyester and polycarbonate materials into small organic molecules. Certain polar organic solvents exhibit remarkable efficiency in polymer degradation under catalyst-free conditions. Employing these polar solvents, both polymer resins and commercially available products could be effectively degraded via alcoholysis. Our design contributes a straightforward route for recycling waste polymeric materials.
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Affiliation(s)
- Qiao Zhang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Chenyang Hu
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Peng-Yuan Li
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, China
| | - Fu-Quan Bai
- Institute of Theoretical Chemistry, College of Chemistry, Jilin University, Changchun 130023, China
- Chongqing Research Institute, Jilin University, Chongqing 401120, China
| | - Xuan Pang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
| | - Xuesi Chen
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun 130022, China
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4
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Christoff-Tempesta T, Epps TH. Ionic-Liquid-Mediated Deconstruction of Polymers for Advanced Recycling and Upcycling. ACS Macro Lett 2023; 12:1058-1070. [PMID: 37516988 PMCID: PMC10433533 DOI: 10.1021/acsmacrolett.3c00276] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 06/26/2023] [Indexed: 08/01/2023]
Abstract
Ionic liquids (ILs) are a promising medium to assist in the advanced (chemical and biological) recycling of polymers, owing to their tunable catalytic activity, tailorable chemical functionality, low vapor pressures, and thermal stability. These unique physicochemical properties, combined with ILs' capacity to solubilize plastics waste and biopolymers, offer routes to deconstruct polymers at reduced temperatures (and lower energy inputs) versus conventional bulk and solvent-based methods, while also minimizing unwanted side reactions. In this Viewpoint, we discuss the use of ILs as catalysts and mediators in advanced recycling, with an emphasis on chemical recycling, by examining the interplay between IL chemistry and deconstruction thermodynamics, deconstruction kinetics, IL recovery, and product recovery. We also consider several potential environmental benefits and concerns associated with employing ILs for advanced recycling over bulk- or solvent-mediated deconstruction techniques, such as reduced chemical escape by volatilization, decreased energy demands, toxicity, and environmental persistence. By analyzing IL-mediated polymer deconstruction across a breadth of macromolecular systems, we identify recent innovations, current challenges, and future opportunities in IL application toward circular polymer economies.
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Affiliation(s)
- Ty Christoff-Tempesta
- Department
of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Thomas H. Epps
- Department
of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
- Department
of Materials Science and Engineering, University
of Delaware, Newark, Delaware 19716, United States
- Center
for Research in Soft matter and Polymers (CRiSP), University of Delaware, Newark, Delaware 19716, United States
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5
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Kirchhecker S, Nguyen N, Reichert S, Lützow K, Eselem Bungu PS, Jacobi von Wangelin A, Sandl S, Neffe AT. Iron(ii) carboxylates and simple carboxamides: an inexpensive and modular catalyst system for the synthesis of PLLA and PLLA-PCL block copolymers. RSC Adv 2023; 13:17102-17113. [PMID: 37293470 PMCID: PMC10244980 DOI: 10.1039/d3ra03112h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 05/30/2023] [Indexed: 06/10/2023] Open
Abstract
The combination of inexpensive Fe(ii) acetate with low molecular weight aliphatic carboxamides in situ generates an effective catalyst system for the ring opening polymerisation of lactones. PLLAs were produced in melt conditions with molar masses of up to 15 kg mol-1, narrow dispersity (Đ = 1.03), and without racemisation. The catalytic system was investigated in detail with regard to Fe(ii) source, and steric and electronic effects of the amide's substituents. Furthermore, the synthesis of PLLA-PCL block copolymers of very low randomness was achieved. This commercially available, inexpensive, modular, and user-friendly catalyst mixture may be suitable for polymers with biomedical applications.
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Affiliation(s)
- Sarah Kirchhecker
- Institute of Active Polymers, Helmholtz-Zentrum Hereon Kantstr. 55 14513 Teltow Germany
| | - Ngoc Nguyen
- Institute for Technical and Macromolecular Chemistry, University of Hamburg Bundesstrasse 55 20146 Hamburg Germany
| | - Stefan Reichert
- Department of Chemistry, University of Hamburg Martin-Luther-King-Platz 6 20146 Hamburg Germany
| | - Karola Lützow
- Institute of Active Polymers, Helmholtz-Zentrum Hereon Kantstr. 55 14513 Teltow Germany
| | - Paul S Eselem Bungu
- Institute of Active Polymers, Helmholtz-Zentrum Hereon Kantstr. 55 14513 Teltow Germany
| | | | - Sebastian Sandl
- Department of Chemistry, University of Hamburg Martin-Luther-King-Platz 6 20146 Hamburg Germany
| | - Axel T Neffe
- Institute of Active Polymers, Helmholtz-Zentrum Hereon Kantstr. 55 14513 Teltow Germany
- Institute for Technical and Macromolecular Chemistry, University of Hamburg Bundesstrasse 55 20146 Hamburg Germany
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6
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Burkart L, Eith A, Hoffmann A, Herres-Pawlis S. Open Loop Recycling - Guanidine Iron(II) Polymerization Catalyst for the Depolymerization of Polylactide. Chem Asian J 2023; 18:e202201195. [PMID: 36577118 DOI: 10.1002/asia.202201195] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 12/30/2022]
Abstract
A previously reported non-toxic guanidine-iron catalyst active in the ring opening polymerization (ROP) of polylactide (PLA) under industrially relevant conditions was evaluated for its activity in the alcoholysis and aminolysis of PLA under mild conditions. Kinetic and thermodynamic parameters were determined for the methanolysis of PLA with [FeCl2 (TMG5NMe2 asme)] (C1) using 1 H NMR spectroscopy. A comparison with the Zn analog of C1 showed that the metal center has a large impact on the activity for the alcoholysis. Further, the influence of different nucleophiles was tested broadening the scope of products from PLA waste. C1 is the first discrete metal catalyst reported to be active in the selective aminolysis of PLA. Catalyst recycling, scale-up experiments and solvent-free alcoholysis were conducted successfully strengthening the industrial relevance and highlighting aspects of green chemistry. Moreover, the selective depolymerization of PLA in polymer blends was successful. C1 is a promising catalyst for a circular (bio)plastics economy.
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Affiliation(s)
- Lisa Burkart
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074, Aachen, Germany
| | - Alexander Eith
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074, Aachen, Germany
| | - Alexander Hoffmann
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074, Aachen, Germany
| | - Sonja Herres-Pawlis
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074, Aachen, Germany
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7
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Fuchs M, Walbeck M, Jagla E, Hoffmann A, Herres-Pawlis S. Guanidine Carboxy Zinc Complexes for the Chemical Recycling of Renewable Polyesters. Chempluschem 2022; 87:e202200029. [DOI: 10.1002/cplu.202200029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 02/22/2022] [Indexed: 11/11/2022]
Affiliation(s)
- Martin Fuchs
- RWTH Aachen University: Rheinisch-Westfalische Technische Hochschule Aachen Chemistry GERMANY
| | - Marcel Walbeck
- RWTH Aachen University: Rheinisch-Westfalische Technische Hochschule Aachen Chemistry GERMANY
| | - Eveline Jagla
- RWTH Aachen University: Rheinisch-Westfalische Technische Hochschule Aachen Chemistry GERMANY
| | - Alexander Hoffmann
- RWTH Aachen University: Rheinisch-Westfalische Technische Hochschule Aachen Chemistry GERMANY
| | - Sonja Herres-Pawlis
- RWTH Aachen Fakultät 1, Institut für Anorganische Chemie Landoltweg 1 52074 Aachen GERMANY
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8
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Stewart J, Fuchs M, Payne J, Driscoll O, Kociok-Köhn G, Ward BD, Herres-Pawlis S, Jones MD. Simple Zn(ii) complexes for the production and degradation of polyesters. RSC Adv 2022; 12:1416-1424. [PMID: 35425174 PMCID: PMC8979053 DOI: 10.1039/d1ra09087a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 11/21/2022] Open
Abstract
Nine new complexes based on thioether appended iminophenolate (ONS) ligands have been prepared and fully characterized in solution by NMR spectroscopy. Solid-state structures were also obtained for seven complexes. In solution, all complexes were monomeric. The complexes were highly active for the polymerization of purified rac-lactide ([M] : [Zn] : [BnOH] = 10 000 : 1 : 30 at 180 °C) reaching TOF values up to 250 000 h−1. The kinetics of the polymerization have been probed by in situ Raman spectroscopy. The rate of reaction was dramatically reduced using technical grade rac-lactide with increased initiator loading. To move towards a circular economy, it is vital that catalysts are developed to facilitate chemical recycling of commodity and emerging polymeric materials. In this vein, the complexes have been assessed for their ability to break down poly(lactic acid) and poly(ethylene terephthalate). The results from both the polymerization and degradation reactions are discussed in terms of ligand functionality. Nine new complexes based on thioether appended iminophenolate (ONS) ligands have been prepared and fully characterized in solution by NMR spectroscopy.![]()
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Affiliation(s)
- Jack Stewart
- Department of Chemistry, University of Bath, Claverton Down, Bath BA27AY, UK
| | - Martin Fuchs
- Lehrstuhl für Bioanorganische Chemie, Institut für Anorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Jack Payne
- Department of Chemistry, University of Bath, Claverton Down, Bath BA27AY, UK
| | - Oliver Driscoll
- Department of Chemistry, University of Bath, Claverton Down, Bath BA27AY, UK
| | | | - Benjamin D. Ward
- Department of Chemistry, Cardiff University, Park Place, Cardiff, CF10 3AT, UK
| | - Sonja Herres-Pawlis
- Lehrstuhl für Bioanorganische Chemie, Institut für Anorganische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
| | - Matthew D. Jones
- Department of Chemistry, University of Bath, Claverton Down, Bath BA27AY, UK
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9
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Santulli F, Lamberti M, Mazzeo M. A Single Catalyst for Promoting Reverse Processes: Synthesis and Chemical Degradation of Polylactide. CHEMSUSCHEM 2021; 14:5470-5475. [PMID: 34612598 PMCID: PMC9298063 DOI: 10.1002/cssc.202101518] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Revised: 10/01/2021] [Indexed: 06/13/2023]
Abstract
A simple zinc catalyst showing high activity for both the synthesis of polylactide, a biodegradable polymer produced from renewable feedstock, and its degradation was described. In the ring-opening polymerization of lactides, the zinc catalyst showed one of the highest activities reported in the literature for reactions carried out in solution at room temperature. This excellent performance was preserved even when the process was performed under industrial conditions: at high temperature, in the absence of solvent, and by using a low catalyst loading with unpurified monomers. The same complex revealed high efficiency also in depolymerization of polylactide by alcoholysis, a process that occurred efficiently at room temperature and in the absence of solvent, conditions that reduce costs and guarantee low environmental impact.
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Affiliation(s)
- Federica Santulli
- Dipartimento di Chimica e Biologia “Adolfo Zambelli”University of Salernovia Giovanni Paolo IISA 132-84084FiscianoItaly
| | - Marina Lamberti
- Dipartimento di Chimica e Biologia “Adolfo Zambelli”University of Salernovia Giovanni Paolo IISA 132-84084FiscianoItaly
| | - Mina Mazzeo
- Dipartimento di Chimica e Biologia “Adolfo Zambelli”University of Salernovia Giovanni Paolo IISA 132-84084FiscianoItaly
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10
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Alberti C, Enthaler S. Ruthenium‐catalyzed Chemical Recycling of Poly(ϵ‐caprolactone) via Hydrogenative Depolymerization and Dehydrogenative Polymerization. ChemistrySelect 2021. [DOI: 10.1002/slct.202103366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Christoph Alberti
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
| | - Stephan Enthaler
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
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11
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Payne J, Jones MD. The Chemical Recycling of Polyesters for a Circular Plastics Economy: Challenges and Emerging Opportunities. CHEMSUSCHEM 2021; 14:4041-4070. [PMID: 33826253 PMCID: PMC8518041 DOI: 10.1002/cssc.202100400] [Citation(s) in RCA: 65] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/01/2021] [Indexed: 05/05/2023]
Abstract
Whilst plastics have played an instrumental role in human development, growing environmental concerns have led to increasing public scrutiny and demands for outright bans. This has stimulated considerable research into renewable alternatives, and more recently, the development of alternative waste management strategies. Herein, the aim was to highlight recent developments in the catalytic chemical recycling of two commercial polyesters, namely poly(lactic acid) (PLA) and poly(ethylene terephthalate) (PET). The concept of chemical recycling is first introduced, and associated opportunities/challenges are discussed within the context of the governing depolymerisation thermodynamics. Chemical recycling methods for PLA and PET are then discussed, with a particular focus on upcycling and the use of metal-based catalysts. Finally, the attention shifts to the emergence of new materials with the potential to modernise the plastics economy. Emerging opportunities and challenges are discussed within the context of industrial feasibility.
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Affiliation(s)
- Jack Payne
- Centre for Sustainable and Circular TechnologiesUniversity of Bath Claverton DownBathBA2 7AYUK
| | - Matthew D. Jones
- Department of ChemistryUniversity of Bath Claverton DownBathBA2 7AYUK
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12
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Cheung E, Alberti C, Bycinskij S, Enthaler S. Zinc‐Catalyzed Chemical Recycling of Poly(ϵ‐caprolactone) Applying Transesterification Reactions. ChemistrySelect 2021. [DOI: 10.1002/slct.202004294] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Even Cheung
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D–20146 Hamburg Germany
| | - Christoph Alberti
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D–20146 Hamburg Germany
| | - Sergej Bycinskij
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D–20146 Hamburg Germany
| | - Stephan Enthaler
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D–20146 Hamburg Germany
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13
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Alberti C, Matthiesen K, Wehrmeister M, Bycinskij S, Enthaler S. Zinc‐Catalyzed Depolymerization of the End‐of‐Life Poly(ethylene 2,5‐furandicarboxylate). ChemistrySelect 2021. [DOI: 10.1002/slct.202102427] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Christoph Alberti
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
| | - Konstantin Matthiesen
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
| | - Moritz Wehrmeister
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
| | - Sergej Bycinskij
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
| | - Stephan Enthaler
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
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14
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Synergistic Dual Catalytic System and Kinetics for the Alcoholysis of Poly(Lactic Acid). Processes (Basel) 2021. [DOI: 10.3390/pr9060921] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Plastic pollution is a global issue that is approaching crisis levels as plastic production is projected to reach 1.1 GT annually by 2050. The bioplastic industry along with a circular production economy are solutions to this problem. One promising bioplastic polylactic acid (PLA) has mechanical properties comparable to polystyrene (PS), so it could replace PS in its applications as a more environmentally sustainable material. However, since the bioplastic PLA also suffers from long biodegradation times in the environment, to ensure that it does not add to the current pollution problem, it should instead be chemically recycled. In this work, PLA was chemically recycled via alcoholysis, using either methanol or ethanol to generate the value-added products methyl lactate and ethyl lactate respectively. Two catalysts, zinc acetate dihydrate (ZnAc) and 4-(dimethylamino)pyridine (DMAP), were tested both individually and in mixtures. A synergistic effect was exhibited on the reaction rate when both catalysts were used in an equal ratio. The methanolysis reaction was determined to be two-step, with the activation energy estimated to be 73 kJ mol−1 for the first step and 40.16 kJ mol−1 for the second step. Both catalysts are cheap and commercially available, their synergistic effect could be exploited for large-scale PLA recycling.
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15
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Alberti C, Enthaler S. Depolymerization of End‐of‐Life Poly(lactide) to Lactide via Zinc‐Catalysis. ChemistrySelect 2020. [DOI: 10.1002/slct.202003979] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Christoph Alberti
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
| | - Stephan Enthaler
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
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16
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Cheung E, Alberti C, Enthaler S. Chemical Recycling of End-of-Life Poly(lactide) via Zinc-Catalyzed Depolymerization and Polymerization. ChemistryOpen 2020; 9:1224-1228. [PMID: 33304737 PMCID: PMC7705614 DOI: 10.1002/open.202000243] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/12/2020] [Indexed: 01/08/2023] Open
Abstract
The chemical recycling of poly(lactide) was investigated based on depolymerization and polymerization processes. Using methanol as depolymerization reagent and zinc salts as catalyst, poly(lactide) was depolymerized to methyl lactate applying microwave heating. An excellent performance was observed for zinc(II) acetate with turnover frequencies of up to 45000 h-1. In a second step the monomer methyl lactate was converted to (pre)poly(lactide) in the presence of catalytic amounts of zinc salts. Here zinc(II) triflate revealed excellent performance for the polymerization process (yield: 91 %, Mn ∼8970 g/mol). Moreover, the (pre)poly(lactide) was depolymerized to lactide, the industrial relevant molecule for accessing high molecular weight poly(lactide), using zinc(II) acetate as catalyst.
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Affiliation(s)
- Even Cheung
- Universität HamburgInstitut für Anorganische und Angewandte ChemieMartin-Luther-King-Platz 6D-20146HamburgGermany
| | - Christoph Alberti
- Universität HamburgInstitut für Anorganische und Angewandte ChemieMartin-Luther-King-Platz 6D-20146HamburgGermany
| | - Stephan Enthaler
- Universität HamburgInstitut für Anorganische und Angewandte ChemieMartin-Luther-King-Platz 6D-20146HamburgGermany
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17
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Alberti C, Kricheldorf HR, Enthaler S. Application of Bismuth Catalysts for the Methanolysis of End‐of‐Life Poly(lactide). ChemistrySelect 2020. [DOI: 10.1002/slct.202003389] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Christoph Alberti
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
| | - Hans Rytger Kricheldorf
- Universität Hamburg Institut für Technische und Makromolekulare Chemie Bundesstr. 45 D-20146 Hamburg Germany
| | - Stephan Enthaler
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D-20146 Hamburg Germany
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18
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Hofmann M, Sundermeier J, Alberti C, Enthaler S. Zinc(II) acetate Catalyzed Depolymerization of Poly(ethylene terephthalate). ChemistrySelect 2020. [DOI: 10.1002/slct.202002260] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Melanie Hofmann
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D–20146 Hamburg Germany
| | - Jannis Sundermeier
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D–20146 Hamburg Germany
| | - Christoph Alberti
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D–20146 Hamburg Germany
| | - Stephan Enthaler
- Universität Hamburg Institut für Anorganische und Angewandte Chemie Martin-Luther-King-Platz 6 D–20146 Hamburg Germany
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19
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Abstract
Alkyl lactates are green solvents that are successfully employed in several industries such as pharmaceutical, food and agricultural. They are considered prospective renewable substitutes for petroleum-derived solvents and the opportunity exists to obtain these valuable chemicals from the chemical recycling of waste poly(lactic acid). Alkyl lactates (ethyl lactate, propyl lactate and butyl lactate) were obtained from the catalysed alcoholysis reaction of poly(lactic acid) with the corresponding linear alcohol. Reactions were catalysed by a Zn complex synthesised from an ethylenediamine Schiff base. The reactions were studied in the 50–130 °C range depending on the alcohol, at autogenous pressure. Arrhenius temperature-dependent parameters (activation energies and pre-exponential factors) were estimated for the formation of the lactates. The activation energies (Ea1, Ea2 and Ea−2) for alcoholysis in ethanol were 62.58, 55.61 and 54.11 kJ/mol, respectively. Alcoholysis proceeded fastest in ethanol in comparison to propanol and butanol and reasonable rates can be achieved in temperatures as low as 50 °C. This is a promising reaction that could be used to recycle end-of-life poly(lactic acid) and could help create a circular production economy.
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20
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Román-Ramírez LA, McKeown P, Shah C, Abraham J, Jones MD, Wood J. Chemical Degradation of End-of-Life Poly(lactic acid) into Methyl Lactate by a Zn(II) Complex. Ind Eng Chem Res 2020; 59:11149-11156. [PMID: 32581423 PMCID: PMC7304880 DOI: 10.1021/acs.iecr.0c01122] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/24/2020] [Accepted: 05/01/2020] [Indexed: 02/08/2023]
Abstract
The catalyzed methanolysis of end-of-life poly(lactic acid) (PLA) products by an ethylenediamine Zn(II) complex to form biodegradable methyl lactate was studied experimentally at 70, 90, and 110 °C. The PLA samples consisted of typical consumer waste materials, including a cup, a toy, and a three-dimensional (3D) printing material. High selectivities and yields (>94%) were possible depending on temperature and reaction time. Additionally, and to develop a predictive kinetic model, kinetic parameters (pre-exponential factor and activation energies) of the PLA transesterification reaction were first obtained from virgin PLA. These parameters were subsequently used to estimate the conversion of PLA, selectivity, and yield of methyl lactate after 1 and 4 h of the reaction, and the results were compared with the experimental values of the end-of-life PLA. Despite the presence of unknown additives in the PLA waste material and uncontrolled particle size, the model was able to predict the overall conversion, selectivity, and yield to an average deviation of 5, 7, and 12%, respectively. A greater agreement between the model and experimental values is observed for the higher temperatures and the longer reaction time. Larger deviations were observed for the PLA toy, which we attribute to the presence of additives, since despite its lower molecular weight, it possessed a higher structural strength.
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Affiliation(s)
- Luis A Román-Ramírez
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Paul McKeown
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Chanak Shah
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Joshua Abraham
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Matthew D Jones
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Joseph Wood
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
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21
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Kindler T, Alberti C, Fedorenko E, Santangelo N, Enthaler S. Ruthenium-Catalyzed Hydrogenative Degradation of End-of-Life Poly(lactide) to Produce 1,2-Propanediol as Platform Chemical. ChemistryOpen 2020; 9:401-404. [PMID: 32257748 PMCID: PMC7110137 DOI: 10.1002/open.202000050] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/06/2020] [Indexed: 11/18/2022] Open
Abstract
The chemical recycling of end-of-life polymers can add some value to a future circular economy. In this regard, the hydrogenative degradation of end-of-life PLA was investigated to produce 1,2-propanediol as product, which is a useful building block in polymer chemistry. In more detail, the commercially available Ru-MACHO-BH complex was applied as catalyst to degrade end-of-life PLA efficiently to 1,2-propanediol under mild conditions. After investigations of the reaction conditions a set of end-of-life PLA goods were subjected to degradation.
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Affiliation(s)
- Tim‐Oliver Kindler
- Universität HamburgInstitut für Anorganische und Angewandte ChemieMartin-Luther-King-Platz 620146HamburgGermany
| | - Christoph Alberti
- Universität HamburgInstitut für Anorganische und Angewandte ChemieMartin-Luther-King-Platz 620146HamburgGermany
| | - Elena Fedorenko
- Universität HamburgInstitut für Anorganische und Angewandte ChemieMartin-Luther-King-Platz 620146HamburgGermany
| | - Nicolo Santangelo
- Universität HamburgInstitut für Anorganische und Angewandte ChemieMartin-Luther-King-Platz 620146HamburgGermany
| | - Stephan Enthaler
- Universität HamburgInstitut für Anorganische und Angewandte ChemieMartin-Luther-King-Platz 620146HamburgGermany
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22
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Román-Ramírez LA, McKeown P, Jones MD, Wood J. Kinetics of Methyl Lactate Formation from the Transesterification of Polylactic Acid Catalyzed by Zn(II) Complexes. ACS OMEGA 2020; 5:5556-5564. [PMID: 32201849 PMCID: PMC7081642 DOI: 10.1021/acsomega.0c00291] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 02/20/2020] [Indexed: 05/21/2023]
Abstract
The kinetics of the transesterification of polylactic acid (PLA) with methanol to form methyl lactate catalyzed by Zn(II) complexes was studied experimentally and numerically. The complexes, Zn(1 Et )2 and Zn(2 Pr )2, were synthesized from ethylenediamine and propylenediamine Schiff bases, respectively. The temperature range covered was 313.2-383.2 K. An increase in the reaction rate with the increase in temperature was observed for the Zn(1 Et )2-catalyzed reaction. The temperature relationship of the rate coefficients can be explained by a linear Arrhenius dependency with constant activation energy. The kinetics of Zn(2 Pr )2, on the other hand, is only explained by non-Arrhenius kinetics with convex variable activation energy, resulting in faster methyl lactate production rates at 323.2 and 343.2 K. The formation of a new catalyst species, likely through reaction with protic reagents, appears to promote the formation of intermediate complexes, resulting in the nonlinear behavior. Stirring speed induced the stability of the intermediate complexes. Contrary to Zn(1 Et )2, Zn(2 Pr )2 was susceptible to the presence of air/moisture in solution. The kinetic parameters were obtained by fitting the experimental data to the mass and energy balance of a consecutive second step reversible reaction taking place in a jacketed stirred batch reactor. For the case of Zn(2 Pr )2, the activation energy was fitted to a four-parameter equation. The kinetic parameters presented in this work are valuable for the design of processes involving the chemical recycling of PLA into green solvents.
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Affiliation(s)
- Luis A. Román-Ramírez
- School
of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
| | - Paul McKeown
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2
7AY, U.K.
| | - Matthew D. Jones
- Department
of Chemistry, University of Bath, Claverton Down, Bath BA2
7AY, U.K.
- E-mail: . Phone: +44 (0)1225 384908. Fax: +44 (0)1225
386231 (M.D.J.)
| | - Joseph Wood
- School
of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K.
- E-mail: . Phone: +44 (0) 121
414 5295. Fax: +44 (0) 121
414 5324 (J.W.)
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23
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Payne J, McKeown P, Mahon MF, Emanuelsson EAC, Jones MD. Mono- and dimeric zinc(ii) complexes for PLA production and degradation into methyl lactate – a chemical recycling method. Polym Chem 2020. [DOI: 10.1039/d0py00192a] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A series of well-defined mono- and dimeric Zn(ii)-complexes were prepared and fully characterised by X-ray crystallography and NMR spectroscopy.
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Affiliation(s)
- Jack Payne
- Centre for Sustainable and Circular Technologies
- University of Bath
- Bath
- UK
| | - Paul McKeown
- Centre for Sustainable and Circular Technologies
- University of Bath
- Bath
- UK
| | | | - Emma A. C. Emanuelsson
- Centre for Sustainable and Circular Technologies
- University of Bath
- Bath
- UK
- Department of Chemical Engineering
| | - Matthew D. Jones
- Centre for Sustainable and Circular Technologies
- University of Bath
- Bath
- UK
- Department of Chemistry
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24
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Thongkham S, Monot J, Martin-Vaca B, Bourissou D. Simple In-Based Dual Catalyst Enables Significant Progress in ε-Decalactone Ring-Opening (Co)polymerization. Macromolecules 2019. [DOI: 10.1021/acs.macromol.9b01511] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Somprasong Thongkham
- Laboratoire Hétérochimie Fondamentale et Appliquée (UMR 5069), Université de Toulouse (UPS), CNRS, 118 route de Narbonne, F-31062 Toulouse, France
| | - Julien Monot
- Laboratoire Hétérochimie Fondamentale et Appliquée (UMR 5069), Université de Toulouse (UPS), CNRS, 118 route de Narbonne, F-31062 Toulouse, France
| | - Blanca Martin-Vaca
- Laboratoire Hétérochimie Fondamentale et Appliquée (UMR 5069), Université de Toulouse (UPS), CNRS, 118 route de Narbonne, F-31062 Toulouse, France
| | - Didier Bourissou
- Laboratoire Hétérochimie Fondamentale et Appliquée (UMR 5069), Université de Toulouse (UPS), CNRS, 118 route de Narbonne, F-31062 Toulouse, France
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