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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Zhang Q, Hu C, Pang X, Chen X. Multi-Functional Organofluoride Catalysts for Polyesters Production and Upcycling Degradation. CHEMSUSCHEM 2024; 17:e202300907. [PMID: 37735092 DOI: 10.1002/cssc.202300907] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 09/03/2023] [Accepted: 09/21/2023] [Indexed: 09/23/2023]
Abstract
The production and degradation of polyesters are two crucial processes in polyester materials' life cycle. In this work, multi-functional organocatalysts based on fluorides for both processes are described. Organofluorides were developed as catalysts for ring-opening polymerization of lactide (lactone). Compared with a series of organohalides, organofluoride performed the best catalytic reactivity because of the hydrogen bond interaction between F- and alcohol initiator. The Mn values of polyester products could be up to 72 kg mol-1 . With organofluoride catalysts, the ring-opening copolymerization between various anhydrides and epoxides could be established. Furthermore, terpolymerization of anhydride, epoxide, and lactide could be constructed by the self-switchable organofluoride catalyst to yield a block polymer with a strictly controlled polymerization sequence. Organofluorides were also efficient catalysts for upcycling polyester plastic wastes via alcoholysis. Mixed polyester materials could also be hierarchically recycled.
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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, 130022, Changchun, China
| | - Chenyang Hu
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, 130022, Changchun, China
| | - Xuan Pang
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, 130022, Changchun, China
| | - Xuesi Chen
- Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, 130022, Changchun, China
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3
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Vaillant-Coindard V, Chotard F, Théron B, Balan C, Bayardon J, Malacea-Kabbara R, Bodio E, Rousselin Y, Fleurat-Lessard P, Gendre PL. Bis(salicylamidine) Ligands (FAlen): A Variant of Salen with "à la Carte" Denticity. Inorg Chem 2023; 62:7342-7352. [PMID: 37116183 DOI: 10.1021/acs.inorgchem.3c00493] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Ethylene- and phenylene-bridged bis(salicylamidine) ligands have been readily prepared from ethylene or phenylenediamine and iminium chloride derivatives generated in situ from N,N-dialkylsalicylamides. The former, in its diprotonated form (FAlenH2), reacts with AlMe3 to afford a zwitterionic dimethyldiphenoxyaluminate complex with the FAlen ligand monoprotonated and in a bidentate κ2O,O' fashion. A phenylene-bridged proligand behaves differently, yielding a neutral methylaluminum complex bearing a κ3O,N,O'-coordinated FAlen ligand. From these complexes, methyl anion abstraction with B(C6F5)3 or a reaction with Schrock's alcohol leads to the corresponding aluminum cationic or alkoxy complexes in which a κ4O,N,N',O'-coordination mode of the FAlen ligand is observed. X-ray diffraction studies of the proligands and of the complexes show that the amidine functions feature a trans configuration when the N-amidine atom is not coordinated to the metal and conversely a cis configuration when it is. Density functional theory calculations show that trans-cis isomerization of the amidine functions occurs upon coordination with the metal ion with very low energy barriers. They also confirm the intuition that the denticity of the FAlen ligands in the complexes is directly related to the electron richness of the metal ion. At last, FAlen Al complexes are used as initiators for the controlled ring-opening polymerization of rac-lactide to afford poly(lactic acid) with slight isotactic bias.
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Affiliation(s)
- Valentin Vaillant-Coindard
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
| | - Florian Chotard
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
| | - Benjamin Théron
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
| | - Cédric Balan
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
| | - Jérôme Bayardon
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
| | - Raluca Malacea-Kabbara
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
| | - Ewen Bodio
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
| | - Yoann Rousselin
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
| | - Paul Fleurat-Lessard
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
| | - Pierre Le Gendre
- Institut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB, UMR-CNRS 6302), Université de Bourgogne, 9 avenue Alain Savary, 21000 Dijon, France
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4
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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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5
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Buchard A, Chuck CJ, Davidson MG, Gobius du Sart G, Jones MD, McCormick SN, Russell AD. A Highly Active and Selective Zirconium-Based Catalyst System for the Industrial Production of Poly(lactic acid). ACS Catal 2023; 13:2681-2695. [PMID: 36846823 PMCID: PMC9942235 DOI: 10.1021/acscatal.2c05690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 01/20/2023] [Indexed: 02/10/2023]
Abstract
The biodegradable, aliphatic polyester poly(lactic acid), PLA, is a leading bio-based alternative to petrochemical-derived plastic materials across a range of applications. Widely reported in the available literature as a benchmark for PLA production via the bulk ring-opening polymerization of lactides is the use of divalent tin catalysts, and particularly tin(II) bis(2-ethylhexanoate). We present an alternative zirconium-based system that combines an inexpensive Group IV metal with the robustness, high activity, control, and designed compatibility with existing facilities and processes, that are required for industrial use. We have carried out a comprehensive kinetic study and applied a combined experimental and theoretical approach to understanding the mechanism by which the polymerization of lactide proceeds in the presence of this system. In the laboratory-scale (20 g) polymerization of recrystallized racemic d,l-lactide (rac-lactide), we have measured catalyst turnover frequencies up to at least 56,000 h-1, and confirmed the reported protocols' resistance toward undesirable epimerization, transesterification, and chain scission processes, deleterious to the properties of the polymer product. Further optimization and scale-up under industrial conditions have confirmed the relevance of the catalytic protocol to the commercial production of melt-polymerized PLA. We were able to undertake the efficient preparation of high-molecular-weight PLA on the 500-2000 g scale, via the selective and well-controlled polymerization of commercial polymer-grade l-lactide under challenging, industrially relevant conditions, and at metal concentrations as low as 8-12 ppm Zr by weight ([Zr] = 1.3 × 10-3 to 1.9 × 10-3 mol %). Under those conditions, a catalyst turnover number of at least 60,000 was attained, and the activity of the catalyst was comparable to that of tin(II) bis(2-ethylhexanoate).
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Affiliation(s)
- Antoine Buchard
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemistry, University of Bath, BathBA2 7AY, U.K.
| | - Christopher J. Chuck
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemical Engineering, University of Bath, BathBA2 7AY, U.K.
| | - Matthew G. Davidson
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemistry, University of Bath, BathBA2 7AY, U.K.,
| | | | - Matthew D Jones
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemistry, University of Bath, BathBA2 7AY, U.K.
| | - Strachan N. McCormick
- Institute
for Sustainability, University of Bath, BathBA2 7AY, U.K.,Department
of Chemistry, University of Bath, BathBA2 7AY, U.K.,
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6
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Zaborowska M, Bernat K. The development of recycling methods for bio-based materials - A challenge in the implementation of a circular economy: A review. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2023; 41:68-80. [PMID: 35765777 PMCID: PMC9925894 DOI: 10.1177/0734242x221105432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 05/14/2022] [Indexed: 06/15/2023]
Abstract
This review focuses on the characteristics of the most widely used biopolymers that contain starch, polylactic acid, cellulose and/or polybutylene succinate. Because worldwide production of bio-based materials has grown dynamically, their waste is increasingly found in the existing waste treatment plants. The development of recycling methods for bio-based materials remains a challenge in the implementation of a circular economy. This article summarizes the recycling methods for bio-based materials, which, in the hierarchy of waste management, is much more desirable than landfilling. Several methods of recycling are available for the end-of-life management of bio-based products, which include mechanical (reuse of waste as a valuable raw material for further processing), chemical (feedstock recycling) and organic (anaerobic digestion or composting) ones. The use of chemical or mechanical recycling is less favourable, more costly and requires the improvement of systems for separation of bio-based materials from the rest of the waste stream. Organic recycling can be a sustainable alternative to those two methods. In organic recycling, bio-based materials can be biologically treated under aerobic or anaerobic conditions, depending on the characteristics of the materials. The choice of the recycling method to be implemented depends on the economic situation and on the properties of the bio-based products and their susceptibility to degradation. Thus, it is necessary to label the products to indicate which method of recycling is most appropriate.
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Affiliation(s)
- Magdalena Zaborowska
- Magdalena Zaborowska, Department of
Environmental Biotechnology, University of Warmia and Mazury in
Olsztyn, Sloneczna 45G, Olsztyn 10-709, Poland.
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7
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Zhou X, Liu Q, Xu G, Yang R, Sun H, Wang Q. Chemical upcycling of poly(lactide) plastic waste to lactate ester, lactide and new poly(lactide) under Mg-catalysis condition. CHINESE CHEM LETT 2023. [DOI: 10.1016/j.cclet.2023.108158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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8
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Liu H, You F, Hu X, Huo Y, Shi X. Rare-Earth Metal Complexes Bearing Unsymmetrical Diarylamido Ligands for Ring-Opening Polymerization of rac-Lactide. Organometallics 2022. [DOI: 10.1021/acs.organomet.2c00446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Hui Liu
- Department of Polymer Materials, School of Materials Science and Engineering, Shanghai University, Materials Building, Nanchen Street 333, Shanghai 200444, China
| | - Fen You
- Department of Polymer Materials, School of Materials Science and Engineering, Shanghai University, Materials Building, Nanchen Street 333, Shanghai 200444, China
| | - Xiang Hu
- Department of Polymer Materials, School of Materials Science and Engineering, Shanghai University, Materials Building, Nanchen Street 333, Shanghai 200444, China
| | - Yanchen Huo
- Department of Polymer Materials, School of Materials Science and Engineering, Shanghai University, Materials Building, Nanchen Street 333, Shanghai 200444, China
| | - Xiaochao Shi
- Department of Polymer Materials, School of Materials Science and Engineering, Shanghai University, Materials Building, Nanchen Street 333, Shanghai 200444, China
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9
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Zinc and magnesium catalysts for the synthesis for PLA and its degradation: Clues for catalyst design. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112480] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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10
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Lamberti FM, Román-Ramírez LA, Dove AP, Wood J. Methanolysis of Poly(lactic Acid) Using Catalyst Mixtures and the Kinetics of Methyl Lactate Production. Polymers (Basel) 2022; 14:polym14091763. [PMID: 35566932 PMCID: PMC9105383 DOI: 10.3390/polym14091763] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 12/04/2022] Open
Abstract
Polylactic acid (PLA) is a leading bioplastic of which the market share is predicted to increase in the future; its growing production capacity means its end-of-life treatment is becoming increasingly important. One beneficial disposal route for PLA is its chemical recycling via alcoholysis. The alcoholysis of PLA leads to the generation of value-added products alkyl lactates; this route also has potential for a circular economy. In this work, PLA was chemically recycled via methanolysis to generate methyl lactate (MeLa). Four commercially available catalysts were investigated: zinc acetate dihydrate (Zn(OAc)2), magnesium acetate tetrahydrate (Mg(OAc)2), 4-(dimethylamino)pyridine (DMAP), and triazabicyclodecene (TBD). Dual catalyst experiments displayed an increase in reactivity when Zn(OAc)2 was paired with TBD or DMAP, or when Mg(OAc)2 was paired with TBD. Zn(OAc)2 coupled with TBD displayed the greatest reactivity. Out of the single catalyst reactions, Zn(OAc)2 exhibited the highest activity: a higher mol% was found to increase reaction rate but plateaued at 4 mol%, and a higher equivalent of methanol was found to increase the reaction rate, but plateaued at 17 equivalents. PLA methanolysis was modelled as a two-step reversible reaction; the activation energies were estimated at: Ea1 = 25.23 kJ∙mol−1, Ea2 = 34.16 kJ∙mol−1 and Ea-2 = 47.93 kJ∙mol−1.
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Affiliation(s)
- Fabio M. Lamberti
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
| | - Luis A. Román-Ramírez
- Division of Chemical and Energy Engineering, London South Bank University, 103 Borough Road, London SE1 0AA, UK;
| | - Andrew P. Dove
- School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
| | - Joseph Wood
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK;
- Correspondence:
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11
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Payne JM, Kamran M, Davidson MG, Jones MD. Versatile Chemical Recycling Strategies: Value-Added Chemicals from Polyester and Polycarbonate Waste. CHEMSUSCHEM 2022; 15:e202200255. [PMID: 35114081 PMCID: PMC9306953 DOI: 10.1002/cssc.202200255] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Indexed: 06/14/2023]
Abstract
ZnII -complexes bearing half-salan ligands were exploited in the mild and selective chemical upcycling of various commercial polyesters and polycarbonates. Remarkably, we report the first example of discrete metal-mediated poly(bisphenol A carbonate) (BPA-PC) methanolysis being appreciably active at room temperature. Indeed, Zn(2)2 and Zn(2)Et achieved complete BPA-PC consumption within 12-18 mins in 2-Me-THF, noting high bisphenol A (BPA) yields (SBPA =85-91 %) within 2-4 h. Further kinetic analysis found such catalysts to possess kapp values of 0.28±0.040 and 0.47±0.049 min-1 respectively at 4 wt%, the highest reported to date. A completely circular upcycling approach to plastic waste was demonstrated through the production of several renewable poly(ester-amide)s (PEAs), based on a terephthalamide monomer derived from bottle-grade poly(ethylene terephthalate) (PET), which exhibited excellent thermal properties.
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Affiliation(s)
- Jack M. Payne
- Centre for Sustainable and Circular TechnologiesUniversity of BathClaverton DownBathBA2 7AYUnited Kingdom
- Department of ChemistryUniversity of BathClaverton DownBathBA2 7AYUnited Kingdom
| | - Muhammad Kamran
- Centre for Sustainable and Circular TechnologiesUniversity of BathClaverton DownBathBA2 7AYUnited Kingdom
- Department of ChemistryUniversity of BathClaverton DownBathBA2 7AYUnited Kingdom
| | - Matthew G. Davidson
- Centre for Sustainable and Circular TechnologiesUniversity of BathClaverton DownBathBA2 7AYUnited Kingdom
- Department of ChemistryUniversity of BathClaverton DownBathBA2 7AYUnited Kingdom
| | - Matthew D. Jones
- Centre for Sustainable and Circular TechnologiesUniversity of BathClaverton DownBathBA2 7AYUnited Kingdom
- Department of ChemistryUniversity of BathClaverton DownBathBA2 7AYUnited Kingdom
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12
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Selective alcoholysis of lactide catalyzed by bulky Lewis pairs of tris(pentafluorophenyl)borane and phosphines. MOLECULAR CATALYSIS 2022. [DOI: 10.1016/j.mcat.2022.112121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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13
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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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14
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Payne JM, Kociok-Köhn G, Emanuelsson EAC, Jones MD. Zn(II)- and Mg(II)-Complexes of a Tridentate {ONN} Ligand: Application to Poly(lactic acid) Production and Chemical Upcycling of Polyesters. Macromolecules 2021. [DOI: 10.1021/acs.macromol.1c01207] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Affiliation(s)
- Jack M. Payne
- Centre for Sustainable and Circular Technologies, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Gabriele Kociok-Köhn
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Emma A. C. Emanuelsson
- Department of Chemical Engineering, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
| | - Matthew D. Jones
- Department of Chemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
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15
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Impemba S, Roviello G, Milione S, Capacchione C. NSSN-Type Group 4 Metal Complexes in the Ring-Opening Polymerization of l-Lactide. Inorg Chem 2021; 60:7561-7572. [PMID: 33909437 DOI: 10.1021/acs.inorgchem.1c01056] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new class of zirconium and hafnium complexes coordinated by linear dianonic tetradentate NSSN ligands is reported. The ligands feature two amide functions coupled with two thioether groups linked by a central flexible ethane bridge and two lateral rigid phenylene bridges and differ for the substituents on the aniline nitrogen atoms, i.e., isopropyl, cyclohexyl, or mesityl substituents: NSSN-iPr, NSSN-Cy, or NSSN-Mes. They were prepared by reacting 2-aminothiophenol with dibromoethane to afford the NSSN ligands without substituents on the aniline nitrogen atoms, which were subsequently alkylated through a reductive amination of acetone or cyclohexanone or palladium-catalyzed cross-coupling reaction with mesityl bromide. The corresponding zirconium and hafnium complexes 1-5 were obtained through a transamination reaction between the neutral ligands and Zr(NMe2)4 or Hf(NMe2)4 [(NSSN-iPr)Zr(NMe2)2 (1), (NSSN-Cy)Zr(NMe2)2 (2), (NSSN-Mes)Zr(NMe2)2 (3), (NSSN-iPr)Hf(NMe2)2 (4), and (NSSN-Cy)Hf(NMe2)2 (5)]. They were characterized in solution by NMR spectroscopy and in solid state by X-ray diffraction analysis (except for 3). All complexes present an octahedral coordination geometry with a fac-fac ligand wrapping and a cis relationship between the other two monodentate ligands. The catalytic performances of 1-5 in the ring-opening polymerization of cyclic esters were investigated. Complex 1 was the most active: its polymerization activity was superior to those generally displayed by zirconium complexes featuring OSSO ligands and compared well with those of the most active group 4 complexes operating in a toluene solution.
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Affiliation(s)
- Salvatore Impemba
- Department of Chemistry and Biology, University of Salerno, via Giovanni Paolo II 132, Fisciano, Salerno I-84084, Italy.,Interuniversity Consortium Chemical Reactivity and Catalysis, via Celso Ulpiani 27, Bari 70126, Italy
| | - Giuseppina Roviello
- Department of Engineering, University of Naples Parthenope, Centro Direzionale, Isola C4, Naples 80143, Italy
| | - Stefano Milione
- Department of Chemistry and Biology, University of Salerno, via Giovanni Paolo II 132, Fisciano, Salerno I-84084, Italy.,Interuniversity Consortium Chemical Reactivity and Catalysis, via Celso Ulpiani 27, Bari 70126, Italy
| | - Carmine Capacchione
- Department of Chemistry and Biology, University of Salerno, via Giovanni Paolo II 132, Fisciano, Salerno I-84084, Italy.,Interuniversity Consortium Chemical Reactivity and Catalysis, via Celso Ulpiani 27, Bari 70126, Italy
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16
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Turner ZR, Lamb JV, Robinson TP, Mandal D, Buffet JC, O Hare D. Ring-opening polymerisation of l- and rac-lactide using group 4 permethylpentalene aryloxides and alkoxides. Dalton Trans 2021; 50:4805-4818. [PMID: 33877178 DOI: 10.1039/d1dt00252j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new family of group 4 permethylpentalene (C8Me62-; Pn*) aryloxide and alkoxide complexes have been synthesised and fully characterised by multinuclear NMR spectroscopy and single-crystal X-ray diffraction; (η8-C8Me6)Zr(OR)2 (R = tBu (1), 2,6-Me-C6H3 (2), 2,6-iPr-C6H3 (3) and 4-OMe-C6H4 (4)), (η8-C8Me6)Zr (OR) (R = 2,6-tBu-C6H3 (5) and 2,6-tBu-4-Me-C6H2 (6)), (η8-C8Me6)ZrCp(OR) (R = tBu (7), 2,6-Me-C6H3 (8) and 2,6-iPr-C6H3 (9)), (η8-C8Me6)TiCp(O-2,6-Me-C6H3) (10) and (η8-C8Me6)ZrCpMe(OR) (R = 2,6-Me-C6H3 (11), 2,6-iPr-C6H3 (12) and 2,4-tBu-C6H3 (13)). 2, 3, 6, 7, 9, 10 and 12 were studied as initiators for the ring-opening polymerisation (ROP) of l-lactide, and 2, 3, 6, 7 and 10 were studied as initiators for the ROP of rac-lactide. 3 was found to be the most active initiator for the ROP of l-lactide (kobs = 0.35 h-1) and 2 for the ROP of rac-lactide (kobs = 0.21 h-1). These initiators produced isotactic PLA for the ROP of l-lactide and moderately heterotactic enriched (maximum Pr of 0.69) or atactic PLA for the ROP of rac-lactide with polymer chains consisting of polylactic acid repeat units with -OR and -OH end groups.
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Affiliation(s)
- Zoë R Turner
- Chemistry Research Laboratory, Department of Chemistry, University of Oxford, 12, Mansfield Road, OX1 3TA, Oxford, UK.
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17
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Liguori F, Moreno-Marrodán C, Barbaro P. Valorisation of plastic waste via metal-catalysed depolymerisation. Beilstein J Org Chem 2021; 17:589-621. [PMID: 33747233 PMCID: PMC7940818 DOI: 10.3762/bjoc.17.53] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2020] [Accepted: 02/05/2021] [Indexed: 12/20/2022] Open
Abstract
Metal-catalysed depolymerisation of plastics to reusable building blocks, including monomers, oligomers or added-value chemicals, is an attractive tool for the recycling and valorisation of these materials. The present manuscript shortly reviews the most significant contributions that appeared in the field within the period January 2010–January 2020 describing selective depolymerisation methods of plastics. Achievements are broken down according to the plastic material, namely polyolefins, polyesters, polycarbonates and polyamides. The focus is on recent advancements targeting sustainable and environmentally friendly processes. Biocatalytic or unselective processes, acid–base treatments as well as the production of fuels are not discussed, nor are the methods for the further upgrade of the depolymerisation products.
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Affiliation(s)
- Francesca Liguori
- Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti Organo Metallici, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy
| | - Carmen Moreno-Marrodán
- Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti Organo Metallici, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy
| | - Pierluigi Barbaro
- Consiglio Nazionale delle Ricerche, Istituto di Chimica dei Composti Organo Metallici, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy
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18
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Phosphasalalen Rare-Earth Complexes for the Polymerization of rac-Lactide and rac-β-Butyrolactone. Inorg Chem 2021; 60:705-717. [PMID: 33405906 DOI: 10.1021/acs.inorgchem.0c02741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A series of new phosphasalalen pro-ligands, analogues of salalen but with an iminophosphorane replacing the imine functionality, and their corresponding rare-earth alkoxide and siloxide complexes were synthesized. The multinuclear NMR spectra and X-ray diffraction analyses revealed that, for the tert-butoxide and ethoxide complexes, the resulting phosphasalalen rare-earth product was composed of a mononuclear alkoxide and a binuclear complex containing bridged alkoxo and hydroxo groups, while an analogous binuclear complex was isolated as the sole product for the siloxide complex. All the complexes could catalyze the heteroselective ring-opening polymerization (ROP) of rac-lactide (Pr up to 0.77) with high catalytic activities and a controlled polydispersity. Remarkably, the yttrium and lutetium phosphasalalen complexes could also efficiently catalyze the ROP of rac-β-butyrolactone to produce syndiotactic polymers (Pr up to 0.73) while their salalen analogues were inert, revealing the special effects of the iminophosphorane moiety. Detailed end-group analyses and kinetic investigations suggested that the alkoxo-hydroxo-bridged complexes maintained their binuclear structures in the polymerization.
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19
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Payne J, McKeown P, Driscoll O, Kociok-Köhn G, Emanuelsson EAC, Jones MD. Make or break: Mg( ii)- and Zn( ii)-catalen complexes for PLA production and recycling of commodity polyesters. Polym Chem 2021. [DOI: 10.1039/d0py01519a] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of Mg(ii) and Zn(ii) catalen complexes have been prepared for PLA formation and recycling.
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Affiliation(s)
- Jack Payne
- Centre for Sustainable and Circular Technologies
- University of Bath
- Claverton Down
- UK
| | - Paul McKeown
- Department of Chemistry
- University of Bath
- Claverton Down
- UK
| | | | | | | | - Matthew D. Jones
- Centre for Sustainable and Circular Technologies
- University of Bath
- Claverton Down
- UK
- Department of Chemistry
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20
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Liu N, Liu D, Liu B, Zhang H, Cui D. Stereoselective polymerization of rac-lactide catalyzed by zwitterionic calcium complexes. Polym Chem 2021. [DOI: 10.1039/d0py01397h] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Two zwitterionic calcium complexes L1CaN(SiMe3)2(THF) (1) and L2CaN(SiMe3)2 (2) via protolysis reaction were synthesized. At −75 °C, 1 gave a heterotactic sequence enriched polylactide, whilst 2 produced an isotactic sequence enriched polymer.
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Affiliation(s)
- Na Liu
- Key Laboratory of Rare and Scattered Elements
- Liaoning University
- Shenyang
- China
| | - Doudou Liu
- College of Chemistry & Chemical Engineering
- Inner Mongolia University
- Hohhot
- China
| | - Bo Liu
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Science
- Changchun
- China
| | - Hao Zhang
- College of Chemistry & Chemical Engineering
- Inner Mongolia University
- Hohhot
- China
| | - Dongmei Cui
- State Key Laboratory of Polymer Physics and Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Science
- Changchun
- China
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21
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Mahmood Q, Xu G, Zhou L, Guo X, Wang Q. Chiral 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD)-Catalyzed Stereoselective Ring-Opening Polymerization of rac-Lactide: High Reactivity for Isotactic Enriched Polylactides (PLAs). Polymers (Basel) 2020; 12:E2365. [PMID: 33076378 PMCID: PMC7602607 DOI: 10.3390/polym12102365] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/21/2020] [Accepted: 09/30/2020] [Indexed: 11/16/2022] Open
Abstract
Chiral 4,8-diphenyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene (DiPh-TBD) was synthesized and applied to a ring-opening polymerization of rac-lactide (rac-LA). The chiral DiPh-TBD promoted the synthesis of isotactic enriched polylactides (PLAs) with controlled molecular weight and narrow molecular weight distributions under mild, metal-free conditions. When the [rac-LA]/[Cat.] ratio was 100/1, full monomer conversion was achieved within only 1 min and a moderate probability of 0.67 meso dyads (Pm) was obtained at room temperature. A chain-end control mechanism (CEC) was found to be responsible for the isoselectivity based on the homodecoupled 1H NMR spectrum, the chiral HPLC measurement, and kinetic studies.
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Affiliation(s)
- Qaiser Mahmood
- Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (Q.M.); (L.Z.); (X.G.)
| | - Guangqiang Xu
- Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (Q.M.); (L.Z.); (X.G.)
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Li Zhou
- Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (Q.M.); (L.Z.); (X.G.)
| | - Xuanhua Guo
- Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (Q.M.); (L.Z.); (X.G.)
| | - Qinggang Wang
- Key Laboratory of Biobased Materials, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China; (Q.M.); (L.Z.); (X.G.)
- Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China
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22
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Feghali E, Tauk L, Ortiz P, Vanbroekhoven K, Eevers W. Catalytic chemical recycling of biodegradable polyesters. Polym Degrad Stab 2020. [DOI: 10.1016/j.polymdegradstab.2020.109241] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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23
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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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24
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Driscoll OJ, Stewart JA, McKeown P, Jones MD. Salalen vs. thiolen: in the ring(-opening of epoxide and cyclic carbonate formation). NEW J CHEM 2020. [DOI: 10.1039/d0nj00725k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A range of Fe(iii)-salalen and -thiolen–chloride complexes have been prepared and are shown to be active catalysts for the selective coupling of CO2 and cyclohexene oxide (CHO).
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Affiliation(s)
| | - Jack A. Stewart
- Department of Chemistry, University of Bath
- Claverton Down
- Bath
- UK
| | - Paul McKeown
- Department of Chemistry, University of Bath
- Claverton Down
- Bath
- UK
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25
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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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26
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Normand AT, Malacea-Kabbara R, Lapenta R, Dajnak A, Richard P, Cattey H, Bolley A, Grassi A, Milione S, Auffrant A, Dagorne S, Le Gendre P. Phosphasalen group IV metal complexes: synthesis, characterization and ring opening polymerization of lactide. Dalton Trans 2020; 49:6989-7004. [DOI: 10.1039/d0dt00972e] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of discrete mononuclear neutral and cationic phosphasalen Ti and Zr complexes has been isolated and characterized. For the first time, a cationic group IV metal complex was found active in the ROP of LA.
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27
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McKeown P, Román-Ramírez LA, Bates S, Wood J, Jones MD. Zinc Complexes for PLA Formation and Chemical Recycling: Towards a Circular Economy. CHEMSUSCHEM 2019; 12:5233-5238. [PMID: 31714680 DOI: 10.1002/cssc.201902755] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 11/01/2019] [Indexed: 05/14/2023]
Abstract
A series of ZnII complexes, based on propylenediamine Schiff bases, have been prepared and fully characterized. X-ray crystallography and NMR spectroscopy identified significant differences in the solid and solution state for the ZnII species. All complexes have been applied to the ring-opening polymerization of l-lactide with emphasis on industrial conditions. High conversion and good molecular weight control were generally achievable for Zn(A-D)2 , and high-molecular-weight poly(lactic acid) (PLA) was prepared in 1 min at a 10 000:1:33 [lactide]/[Zn]/[BnOH] loading. The more active ZnII catalysts were also applied to PLA degradation to alkyl lactate under mild conditions. Zn(A-B)2 demonstrated high activity and selectivity in this process with PLA being consumed within 1 h at 50 °C. Zn(C-D)2 were shown to be less active, and these observations can be related to the catalysts' structure and the degradation mechanism. Initial results for the degradation of poly(ethylene terephthalate) and mixed feeds are also presented, highlighting the broader applicability of the systems presented.
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Affiliation(s)
- Paul McKeown
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Luis A Román-Ramírez
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Samuel Bates
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - Joseph Wood
- School of Chemical Engineering, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Matthew D Jones
- Department of Chemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
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28
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Liu F, Guo J, Zhao P, Gu Y, Gao J, Liu M. Facile synthesis of DBU-based protic ionic liquid for efficient alcoholysis of waste poly(lactic acid) to lactate esters. Polym Degrad Stab 2019. [DOI: 10.1016/j.polymdegradstab.2019.06.028] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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29
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30
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Salalens and Salans Derived from 3‐Aminopyrrolidine: Aluminium Complexation and Lactide Polymerisation. Eur J Inorg Chem 2019. [DOI: 10.1002/ejic.201900417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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31
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Gong Y, Ma H. High performance benzoimidazolyl-based aminophenolate zinc complexes for isoselective polymerization of rac-lactide. Chem Commun (Camb) 2019; 55:10112-10115. [PMID: 31384844 DOI: 10.1039/c9cc04834k] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Zinc complexes supported by achiral benzoimidazolyl-based aminophenolate ligands exhibit high catalytic activities and excellent isoselectivities toward the ring-opening polymerization of rac-lactide under mild conditions.
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Affiliation(s)
- Yanmei Gong
- Shanghai Key Laboratory of Functional Materials Chemistry and Laboratory of Organometallic Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai, 200237, P. R. China.
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32
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Chlupatý T, Bílek M, Merna J, Brus J, RůŽičková Z, Strassner T, RůŽička A. The addition of Grignard reagents to carbodiimides. The synthesis, structure and potential utilization of magnesium amidinates. Dalton Trans 2019; 48:5335-5342. [PMID: 30941391 DOI: 10.1039/c9dt00880b] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Direct synthesis of magnesium amidinates of the general formula [RNC(R1)NR]MgR2 has been performed from appropriate carbodimide and Grignard reagents (R = iPr, Cy, pTol; R1 = Me, nBu; R2 = nBu, Cl, I). Magnesium bisamidinates of the composition [RNC(R1)NR]2Mg(solvent)2 are accessible from [RNC(R1)NR]MgR2 and via the Schlenk-like equilibrium in coordinating solvents. The only isolated amidinatomagnesium halide, preserved in the dinuclear form of {[pTolNC(Me)N-pTol]Mg(THF)}2-μ-(THF)-μ-(Cl)2, has been obtained from the reaction of pTol-N[double bond, length as m-dash]C[double bond, length as m-dash]N-pTol with MeMgCl(THF)n in hexane. The reaction of pTol-N[double bond, length as m-dash]C[double bond, length as m-dash]N-pTol with two equivalents of MeMgI gives an unprecedented dinuclear cyclic adduct {μ-[pTolNC(Me)N-pTol][MgI(OEt2)]2-μ-Me}. The structures of these complexes have been investigated by NMR spectroscopy, sc-XRD and theoretical methods. Selected complexes have been tested as initiators of ring-opening polymerization reactions with various substrates, the copolymerization of oxiranes and CO2 as well as the esterification of lactides.
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Affiliation(s)
- Tomáš Chlupatý
- Department of General and Inorganic Chemistry, Faculty of Chemical Technology, University of Pardubice, Studentská 573, CZ-532 10, Pardubice, Czech Republic.
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33
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Driscoll OJ, Hafford-Tear CH, McKeown P, Stewart JA, Kociok-Köhn G, Mahon MF, Jones MD. The synthesis, characterisation and application of iron(iii)–acetate complexes for cyclic carbonate formation and the polymerisation of lactide. Dalton Trans 2019; 48:15049-15058. [DOI: 10.1039/c9dt03327k] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cracking the whip: Simple iron(iii) acetate complexes have been applied to the catalytic cyclic carbonate formation and lactide ROP.
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34
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Pan Y, Li W, Wei NN, So YM, Lai X, Li Y, Jiang K, He G. Highly active rare-earth metal catalysts for heteroselective ring-opening polymerization of racemic lactide. Dalton Trans 2019; 48:9079-9088. [PMID: 31017172 DOI: 10.1039/c9dt00541b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Rare-earth metal complexes usually exhibit high activities in the ring-opening polymerization (ROP) of lactide, yet only a few scandium complexes have shown satisfactory activity. Herein, we report the synthesis of a series of chiral anilido-oxazoline-supported scandium and yttrium complexes that exhibit high activity in the ROP of racemic lactide (rac-LA). Complexes La-f-Ln(CH2SiMe3)2THF (La-f = 2-(2,6-R2PhN)-phenyl-4-(S)-R'-oxazoline; for 1a-f: L = La-f, Ln = Sc; for 2a-d: L = La-d, Ln = Y) were synthesized via the convenient one-pot reaction of Ln(CH2SiMe3)3(THF)2 (Ln = Sc, Y) with the corresponding proligands. The crystal structures of 1a, 1d, 1e, and 1f were isostructural, adopting a distorted trigonal bipyramidal configuration. Sc complexes 1 showed outstanding activity in the ROP of rac-LA with heteroselectivity. TOFs of up to 720 h-1 and 2910 h-1 were obtained in THF at room temperature and toluene at 60 °C, respectively. To our knowledge, these are the highest activities reported for Sc systems. Y complexes 2 showed higher activity and heteroselectivity than the Sc complexes, with TOFs of up to 1176 h-1 in THF at room temperature. Compared with the ortho-substituent on the anilido moiety, the bulky substituent at the chiral center of the oxazoline ring had a greater effect on controlling the heteroselectivity.
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Affiliation(s)
- Yu Pan
- State Key Laboratory of Fine Chemicals, School of Petroleum and Chemical Engineering, Dalian University of Technology, Panjin 124221, China.
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35
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Román-Ramírez LA, Mckeown P, Jones MD, Wood J. Poly(lactic acid) Degradation into Methyl Lactate Catalyzed by a Well-Defined Zn(II) Complex. ACS Catal 2018. [DOI: 10.1021/acscatal.8b04863] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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
| | - 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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36
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Driscoll OJ, Leung CKC, Mahon MF, McKeown P, Jones MD. Iron(III) Salalen Complexes for the Polymerisation of Lactide. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201801239] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Oliver J. Driscoll
- Department of Chemistry Claverton Down University of Bath BA2 7AY Bath UK
| | | | - Mary F. Mahon
- Department of Chemistry Claverton Down University of Bath BA2 7AY Bath UK
| | - Paul McKeown
- Department of Chemistry Claverton Down University of Bath BA2 7AY Bath UK
| | - Matthew D. Jones
- Department of Chemistry Claverton Down University of Bath BA2 7AY Bath UK
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37
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Group 4 metal complexes containing the salalen ligands: Synthesis, structural characterization and studies on the ROP of cyclic esters. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2018.03.035] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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38
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Harinath A, Bhattacharjee J, Sarkar A, Nayek HP, Panda TK. Ring Opening Polymerization and Copolymerization of Cyclic Esters Catalyzed by Group 2 Metal Complexes Supported by Functionalized P–N Ligands. Inorg Chem 2018; 57:2503-2516. [DOI: 10.1021/acs.inorgchem.7b02847] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Adimulam Harinath
- Department of Chemistry, Indian Institute of Technology Hyderabad Kandi 502 285, Sangareddy, Telangana, India
| | - Jayeeta Bhattacharjee
- Department of Chemistry, Indian Institute of Technology Hyderabad Kandi 502 285, Sangareddy, Telangana, India
| | - Alok Sarkar
- Momentive Performance
Materials Pvt. Ltd., Bangalore 560 100, India
| | - Hari Pada Nayek
- Department of Applied Chemistry, Indian Institute of Technology (ISM), Dhanbad 826 004, Jharkhand, India
| | - Tarun K. Panda
- Department of Chemistry, Indian Institute of Technology Hyderabad Kandi 502 285, Sangareddy, Telangana, India
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39
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Synthesis and structure characterization of homoleptic lanthanide complexes stabilized by Schiff-base ligands and their application in the polymerization of ε-caprolactone. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2017.12.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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40
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Huang Y, Kou X, Duan YL, Ding FF, Yin YF, Wang W, Yang Y. Magnesium and zinc complexes bearing NNO-tridentate ketiminate ligands: synthesis, structures and catalysis in the ring-opening polymerization of lactides. Dalton Trans 2018; 47:8121-8133. [DOI: 10.1039/c8dt00888d] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Magnesium and zinc complexes bearing pyrazoline-derived ketiminate ligands, [(L1–3)2M2(μ-OBn)2] and [M(L)2] proceed through the “coordination–insertion” mechanism in the ROP of lactides.
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Affiliation(s)
- Yong Huang
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Xin Kou
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Yu-Lai Duan
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Fei-Fei Ding
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Yi-Fan Yin
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Wei Wang
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
| | - Ying Yang
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province
- College of Chemistry and Chemical Engineering
- Lanzhou University
- Lanzhou 730000
- P. R. China
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41
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Metz A, McKeown P, Esser B, Gohlke C, Kröckert K, Laurini L, Scheckenbach M, McCormick SN, Oswald M, Hoffmann A, Jones MD, Herres-Pawlis S. ZnII
Chlorido Complexes with Aliphatic, Chiral Bisguanidine Ligands as Catalysts in the Ring-Opening Polymerisation of rac
-Lactide Using FT-IR Spectroscopy in Bulk. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201701147] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Angela Metz
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52074 Germany
| | - Paul McKeown
- Centre for Sustainable Chemical Technologies; Department of Chemistry; University of Bath; Claverton Down BA2 7AY Bath United Kingdom
| | - Bastian Esser
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52074 Germany
| | - Clara Gohlke
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52074 Germany
| | - Konstantin Kröckert
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52074 Germany
| | - Larissa Laurini
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52074 Germany
| | - Michael Scheckenbach
- Department of Chemistry and Pharmacy; Ludwig-Maximlians University Munich; Butenandtstraße 5-13 81377 Munich Germany
| | - Strachan N. McCormick
- Centre for Sustainable Chemical Technologies; Department of Chemistry; University of Bath; Claverton Down BA2 7AY Bath United Kingdom
| | - Michaela Oswald
- Department of Chemistry and Pharmacy; Ludwig-Maximlians University Munich; Butenandtstraße 5-13 81377 Munich Germany
| | - Alexander Hoffmann
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52074 Germany
| | - Matthew D. Jones
- Centre for Sustainable Chemical Technologies; Department of Chemistry; University of Bath; Claverton Down BA2 7AY Bath United Kingdom
| | - Sonja Herres-Pawlis
- Institute of Inorganic Chemistry; RWTH Aachen University; Landoltweg 1 52074 Germany
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42
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Marszałek-Harych A, Jędrzkiewicz D, Ejfler J. Bio- and chemocatalysis cascades as a bridge between biology and chemistry for green polymer synthesis. Cell Mol Biol Lett 2017; 22:28. [PMID: 29225630 PMCID: PMC5715637 DOI: 10.1186/s11658-017-0061-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 11/23/2017] [Indexed: 02/08/2023] Open
Abstract
The development and integration of bio- and chemocatalytic processes to convert renewable or biomass feedstocks into polymers is a vibrant field of research with enormous potential for environmental protection and the mitigation of global warming. Here, we review the biotechnological and chemical synthetic strategies for producing platform monomers from bio-based sources and transforming them into eco-polymers. We also discuss their advanced bio-application using the example of polylactide (PLA), the most valuable green polymer on the market.
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Affiliation(s)
| | - Dawid Jędrzkiewicz
- 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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43
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Reactivity of Zinc Halide Complexes Containing Camphor-Derived Guanidine Ligands with Technical rac-Lactide. INORGANICS 2017. [DOI: 10.3390/inorganics5040085] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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44
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Binuclear aluminum complexes supported by linked bis(β-diketiminate) ligands for ring-opening polymerization of cyclic esters. CHINESE JOURNAL OF POLYMER SCIENCE 2017. [DOI: 10.1007/s10118-018-2053-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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45
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Kan C, Hu J, Huang Y, Wang H, Ma H. Highly Isoselective and Active Zinc Catalysts for rac-Lactide Polymerization: Effect of Pendant Groups of Aminophenolate Ligands. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01420] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Chao Kan
- Shanghai Key Laboratory of
Functional Materials Chemistry and Laboratory of Organometallic Chemistry,
School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Jianwen Hu
- Shanghai Key Laboratory of
Functional Materials Chemistry and Laboratory of Organometallic Chemistry,
School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Yang Huang
- Shanghai Key Laboratory of
Functional Materials Chemistry and Laboratory of Organometallic Chemistry,
School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Haobing Wang
- Shanghai Key Laboratory of
Functional Materials Chemistry and Laboratory of Organometallic Chemistry,
School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
| | - Haiyan Ma
- Shanghai Key Laboratory of
Functional Materials Chemistry and Laboratory of Organometallic Chemistry,
School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
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46
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Synthesis of Li(I), Zn(II) and Mg(II) complexes of amine bis(phenolates) and their exploitation for the ring opening polymerisation of rac-lactide. J Organomet Chem 2017. [DOI: 10.1016/j.jorganchem.2017.08.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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47
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Duan YL, Hu ZJ, Yang BQ, Ding FF, Wang W, Huang Y, Yang Y. Zirconium and hafnium complexes bearing pyrrolidine derived salalen-type {ONNO} ligands and their application for ring-opening polymerization of lactides. Dalton Trans 2017; 46:11259-11270. [PMID: 28799600 DOI: 10.1039/c7dt02113e] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The reactions of pyrrolidine derived salalen-type {ONNO} ligands (S)-L1-3-H2 with 1 equiv. M(OiPr)4(HOiPr) (M = Zr or Hf) in diethyl ether yielded complexes [L1-3M(OiPr)2] (L = L1, M = Zr (1); L = L2, M = Zr (2), Hf (3); L = L3, M = Zr (4), Hf (5)). All of these complexes were well characterized by NMR spectroscopy, elemental analyses and single-crystal X-ray analysis in the case of complexes 1 and 3-5. X-ray structural determination revealed that these complexes were analogous mononuclear species and had a similar structure in which the metal centers were six-coordinated to two oxygen atoms and two nitrogen atoms of one ligand and two oxygen atoms of two isopropoxy groups. All of these complexes efficiently initialized the ring-opening polymerization of lactides to afford polymers with controlled molecular weight and narrow polydispersity. Furthermore, the ring-opening polymerization of rac-lactide catalyzed by complexes 1-5 afforded isotactic-enriched polymers in solution (Pm = 0.74-0.80) and under melt conditions (Pm = 0.63-0.72).
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Affiliation(s)
- Yu-Lai Duan
- Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, Gansu, P. R. China.
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48
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Group 4 Metal Complexes of Phenylene-Salalen Ligands in rac
-Lactide Polymerization Giving High Molecular Weight Stereoblock Poly(lactic acid). Chemistry 2017; 23:11540-11548. [DOI: 10.1002/chem.201701007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2017] [Indexed: 01/19/2023]
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49
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Xu TQ, Yang GW, Liu C, Lu XB. Highly Robust Yttrium Bis(phenolate) Ether Catalysts for Excellent Isoselective Ring-Opening Polymerization of Racemic Lactide. Macromolecules 2017. [DOI: 10.1021/acs.macromol.6b02439] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Tie-Qi Xu
- College
of Chemistry, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, P. R. China
| | - Guan-Wen Yang
- College
of Chemistry, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, P. R. China
- MOE
Laboratory of Macromolecular Synthesis and Functionalization, Department
of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, P. R. China
| | - Chuang Liu
- College
of Chemistry, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, P. R. China
| | - Xiao-Bing Lu
- College
of Chemistry, State Key Laboratory of Fine Chemicals, Dalian University of Technology, Dalian 116024, P. R. China
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50
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McKeown P, Brown-Humes J, Davidson MG, Mahon MF, Woodman TJ, Jones MD. Ligands and complexes based on piperidine and their exploitation of the ring opening polymerisation of rac-lactide. Dalton Trans 2017; 46:5048-5057. [DOI: 10.1039/c7dt00751e] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Ligands based on 2-aminomethyl piperidine have been prepared, complexed to a variety of metals and tested for their ability to polymerise lactide.
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Affiliation(s)
- Paul McKeown
- Doctoral Training Centre in Sustainable Chemical Technologies
- University of Bath
- Bath BA2 7AY
- UK
| | | | - Matthew G. Davidson
- Doctoral Training Centre in Sustainable Chemical Technologies
- University of Bath
- Bath BA2 7AY
- UK
- Department of Chemistry
| | - Mary F. Mahon
- Department of Chemistry
- University of Bath
- Bath BA2 7AY
- UK
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