1
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Mountaki S, Whitfield R, Liarou E, Truong NP, Anastasaki A. Open-Air Chemical Recycling: Fully Oxygen-Tolerant ATRP Depolymerization. J Am Chem Soc 2024; 146:18848-18854. [PMID: 38958656 PMCID: PMC11258787 DOI: 10.1021/jacs.4c05621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2024] [Revised: 06/17/2024] [Accepted: 06/24/2024] [Indexed: 07/04/2024]
Abstract
While oxygen-tolerant strategies have been overwhelmingly developed for controlled radical polymerizations, the low radical concentrations typically required for high monomer recovery render oxygen-tolerant solution depolymerizations particularly challenging. Here, an open-air atom transfer radical polymerization (ATRP) depolymerization is presented, whereby a small amount of a volatile cosolvent is introduced as a means to thoroughly remove oxygen. Ultrafast depolymerization (i.e., 2 min) could efficiently proceed in an open vessel, allowing a very high monomer retrieval to be achieved (i.e., ∼91% depolymerization efficiency), on par with that of the fully deoxygenated analogue. Oxygen probe studies combined with detailed depolymerization kinetics revealed the importance of the low-boiling point cosolvent in removing oxygen prior to the reaction, thus facilitating effective open-air depolymerization. The versatility of the methodology was demonstrated by performing reactions with a range of different ligands and at high polymer loadings (1 M monomer repeat unit concentration) without significantly compromising the yield. This approach provides a fully oxygen-tolerant, facile, and efficient route to chemically recycle ATRP-synthesized polymers, enabling exciting new applications.
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Affiliation(s)
- Stella
Afroditi Mountaki
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Zurich 8093, Switzerland
| | - Richard Whitfield
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Zurich 8093, Switzerland
| | - Evelina Liarou
- Department
of Chemistry, University of Warwick Library Road, Coventry CV4 7SH, U.K.
| | - Nghia P. Truong
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Zurich 8093, Switzerland
| | - Athina Anastasaki
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Zurich 8093, Switzerland
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2
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De Alwis Watuthanthrige N, Whitfield R, Harrisson S, Truong NP, Anastasaki A. Thermal Solution Depolymerization of RAFT Telechelic Polymers. ACS Macro Lett 2024; 13:806-811. [PMID: 38857492 PMCID: PMC11256755 DOI: 10.1021/acsmacrolett.4c00286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/12/2024]
Abstract
Thermal solution depolymerization is a promising low-temperature chemical recycling strategy enabling high monomer recovery from polymers made by controlled radical polymerization. However, current methodologies predominantly focus on the depolymerization of monofunctional polymers, limiting the material scope and depolymerization pathways. Herein, we report the depolymerization of telechelic polymers synthesized by RAFT polymerization. Notably, we observed a significant decrease in the molecular weight (Mn) of the polymers during monomer recovery, which contrasts the minimal Mn shift observed during the depolymerization of monofunctional polymers. Introducing Z groups at the center or both ends of the polymer resulted in distinct kinetic profiles, indicating partial depolymerization of the bifunctional polymers, as supported by mathematical modeling. Remarkably, telechelic polymers featuring R-terminal groups showed up to 68% improvement in overall depolymerization conversion compared to their monofunctional analogues, highlighting the potential of these materials in chemical recycling and the circular economy.
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Affiliation(s)
| | - Richard Whitfield
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Zurich, 8093, Switzerland
| | - Simon Harrisson
- Laboratoire
de Chimie des Polymères Organiques, University of Bordeaux/Bordeaux-INP/CNRS UMR5629, Pessac 33607, France
| | - Nghia P. Truong
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Zurich, 8093, Switzerland
| | - Athina Anastasaki
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Zurich, 8093, Switzerland
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3
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Oh S, Stache EE. Recent advances in oxidative degradation of plastics. Chem Soc Rev 2024; 53:7309-7327. [PMID: 38884337 DOI: 10.1039/d4cs00407h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2024]
Abstract
Oxidative degradation is a powerful method to degrade plastics into oligomers and small oxidized products. While thermal energy has been conventionally employed as an external stimulus, recent advances in photochemistry have enabled photocatalytic oxidative degradation of polymers under mild conditions. This tutorial review presents an overview of oxidative degradation, from its earliest examples to emerging strategies. This review briefly discusses the motivation and the development of thermal oxidative degradation of polymers with a focus on underlying mechanisms. Then, we will examine modern studies primarily relevant to catalytic thermal oxidative degradation and photocatalytic oxidative degradation. Lastly, we highlight some unique studies using unconventional approaches for oxidative polymer degradation, such as electrochemistry.
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Affiliation(s)
- Sewon Oh
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, USA
| | - Erin E Stache
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, USA.
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4
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Zeußel L, Chowdhary S, Wu H, Kumar V, Singh S. Sustainable Harnessing of Waste Polycarbonate for Synthesizing Activated Furans to Generate Stenhouse Adducts on Polymer Surface. Chem Asian J 2024; 19:e202400369. [PMID: 38595045 DOI: 10.1002/asia.202400369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 04/09/2024] [Indexed: 04/11/2024]
Abstract
Plastics are versatile materials, offering lightweight, durable, and affordable solutions across various industries. However, their non-degradable nature poses challenges by end of their life. This study presented an innovative carbonyl extraction method to utilize waste poly(bisphenol A carbonate) (PC) as reaction precursor to synthesis of activated furan as precursor for photoswitchable Stenhouse adducts. This innovative chemical strategy not only generated N,N'-functionalized barbiturates but also provided an eco-friendly and cost-effective alternative to traditional synthesis methods. The method presented hereby not only promotes sustainability by repurposing waste polycarbonate as carbonyl equivalent under green conditions but also yielded reusable bisphenol A (BPA). Furthermore, the derived activated furans exhibited their functionality by forming colored donor-acceptor Stenhouse adducts (DASAs) on aminated polymer surfaces. This work demonstrated a transition from a linear plastics economy toward a circular one, highlighting the potential of plastic waste as a resource for creating materials with improved properties.
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Affiliation(s)
- Lisa Zeußel
- Research Group Bioorganic Chemistry of Bioactive Surfaces, Institute of Chemistry and Biotechnology, Prof-Schmidt-Straße 26, 98693, Ilmenau, Germany
- Department of Nanobiosystem Technology, Institute of Chemistry and Biotechnology, Technical University Ilmenau, Prof-Schmidt-Straße 26, 98693, Ilmenau, Germany
| | | | - Haocheng Wu
- Research Group Bioorganic Chemistry of Bioactive Surfaces, Institute of Chemistry and Biotechnology, Prof-Schmidt-Straße 26, 98693, Ilmenau, Germany
| | - Vipan Kumar
- Department of Chemistry, Guru Nanak Dev University, Amritsar, India
| | - Sukhdeep Singh
- Research Group Bioorganic Chemistry of Bioactive Surfaces, Institute of Chemistry and Biotechnology, Prof-Schmidt-Straße 26, 98693, Ilmenau, Germany
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5
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Sathe D, Yoon S, Wang Z, Chen H, Wang J. Deconstruction of Polymers through Olefin Metathesis. Chem Rev 2024; 124:7007-7044. [PMID: 38787934 DOI: 10.1021/acs.chemrev.3c00748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2024]
Abstract
The consumption of synthetic polymers has ballooned; so has the amount of post-consumer waste generated. The current polymer economy, however, is largely linear with most of the post-consumer waste being either landfilled or incinerated. The lack of recycling, together with the sizable carbon footprint of the polymer industry, has led to major negative environmental impacts. Over the past few years, chemical recycling technologies have gained significant traction as a possible technological route to tackle these challenges. In this regard, olefin metathesis, with its versatility and ease of operation, has emerged as an attractive tool. Here, we discuss the developments in olefin-metathesis-based chemical recycling technologies, including the development of new materials and the application of olefin metathesis to the recycling of commercial materials. We delve into structure-reactivity relationships in the context of polymerization-depolymerization behavior, how experimental conditions influence deconstruction outcomes, and the reaction pathways underlying these approaches. We also look at the current hurdles in adopting these technologies and relevant future directions for the field.
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Affiliation(s)
- Devavrat Sathe
- School of Polymer Science and Polymer Engineering, University of Akron, Akron, Ohio 44325, United States
| | - Seiyoung Yoon
- School of Polymer Science and Polymer Engineering, University of Akron, Akron, Ohio 44325, United States
| | - Zeyu Wang
- School of Polymer Science and Polymer Engineering, University of Akron, Akron, Ohio 44325, United States
| | - Hanlin Chen
- School of Polymer Science and Polymer Engineering, University of Akron, Akron, Ohio 44325, United States
| | - Junpeng Wang
- School of Polymer Science and Polymer Engineering, University of Akron, Akron, Ohio 44325, United States
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6
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Zhang W, Killian L, Thevenon A. Electrochemical recycling of polymeric materials. Chem Sci 2024; 15:8606-8624. [PMID: 38873080 PMCID: PMC11168094 DOI: 10.1039/d4sc01754d] [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: 03/15/2024] [Accepted: 05/17/2024] [Indexed: 06/15/2024] Open
Abstract
Polymeric materials play a pivotal role in our modern world, offering a diverse range of applications. However, they have been designed with end-properties in mind over recyclability, leading to a crisis in their waste management. The recent emergence of electrochemical recycling methodologies for polymeric materials provides new perspectives on closing their life cycle, and to a larger extent, the plastic loop by transforming plastic waste into monomers, building blocks, or new polymers. In this context, we summarize electrochemical strategies developed for the recovery of building blocks, the functionalization of polymer chains as well as paired electrolysis and discuss how they can make an impact on plastic recycling, especially compared to traditional thermochemical approaches. Additionally, we explore potential directions that could revolutionize research in electrochemical plastic recycling, addressing associated challenges.
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Affiliation(s)
- Weizhe Zhang
- Organic Chemistry and Catalysis, Institute for Sustainable and Circular Chemistry, Faculty of Science, Utrecht University Universiteitsweg 99 Utrecht The Netherlands
| | - Lars Killian
- Organic Chemistry and Catalysis, Institute for Sustainable and Circular Chemistry, Faculty of Science, Utrecht University Universiteitsweg 99 Utrecht The Netherlands
| | - Arnaud Thevenon
- Organic Chemistry and Catalysis, Institute for Sustainable and Circular Chemistry, Faculty of Science, Utrecht University Universiteitsweg 99 Utrecht The Netherlands
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7
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Meng XB, Zhou T, Yang C, Cheng XY, Wu XT, Shi C, Du FS, Li ZC. Thermally Stable and Chemically Recyclable Poly(ketal-ester)s Regulated by Floor Temperature. J Am Chem Soc 2024; 146:15428-15437. [PMID: 38795044 DOI: 10.1021/jacs.4c03523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2024]
Abstract
Chemical recycling to monomers (CRM) offers a promising closed-loop approach to transition from current linear plastic economy toward a more sustainable circular paradigm. Typically, this approach has focused on modulating the ceiling temperature (Tc) of monomers. Despite considerable advancements, polymers with low Tc often face challenges such as inadequate thermal stability, exemplified by poly(γ-butyrolactone) (PGBL) with a decomposition temperature of ∼200 °C. In contrast, floor temperature (Tf)-regulated polymers, particularly those synthesized via the ring-opening polymerization (ROP) of macrolactones, inherently exhibit enhanced thermodynamic stability as the temperature increases. However, the development of those Tf regulated chemically recyclable polymers remains relatively underexplored. In this context, by judicious design and efficient synthesis of a biobased macrocyclic diester monomer (HOD), we developed a type of Tf -regulated closed-loop chemically recyclable poly(ketal-ester) (PHOD). First, the entropy-driven ROP of HOD generated high-molar mass PHOD with exceptional thermal stability with a Td,5% reaching up to 353 °C. Notably, it maintains a high Td,5% of 345 °C even without removing the polymerization catalyst. This contrasts markedly with PGBL, which spontaneously depolymerizes back to the monomer above its Tc in the presence of catalyst. Second, PHOD displays outstanding closed-loop chemical recyclability at room temperature within just 1 min with tBuOK. Finally, copolymerization of pentadecanolide (PDL) with HOD generated high-performance copolymers (PHOD-co-PPDL) with tunable mechanical properties and chemical recyclability of both components.
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Affiliation(s)
- Xian-Bin Meng
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing 100871, China
| | - Tong Zhou
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing 100871, China
| | - Chun Yang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing 100871, China
| | - Xiang-Yue Cheng
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing 100871, China
| | - Xiao-Tong Wu
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing 100871, China
| | - Changxia Shi
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing 100871, China
| | - Fu-Sheng Du
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing 100871, China
| | - Zi-Chen Li
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Center for Soft Matter Science and Engineering, College of Chemistry & Molecular Engineering, Peking University, Beijing 100871, China
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8
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Shi C, Diment WT, Chen EYX. Closed-Loop Recycling of Mixed Plastics of Polyester and CO 2-Based Polycarbonate to a Single Monomer. Angew Chem Int Ed Engl 2024:e202405083. [PMID: 38837601 DOI: 10.1002/anie.202405083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Revised: 05/11/2024] [Accepted: 06/03/2024] [Indexed: 06/07/2024]
Abstract
Physical blending is an effective strategy for tailoring polymeric materials to specific application requirements. However, physically blended mixed plastics waste adds additional barriers in mechanical or chemical recycling. This difficulty arises from the intricate requirement for meticulous sorting and separation of the various polymers in the inherent incompatibility of mixed polymers during recycling. To overcome this impediment, this work furthers the emerging single-monomer - multiple-materials approach through the design of a bifunctional monomer that can not only orthogonally polymerize into two different types of polymers - specifically lactone-based polyester and CO2-based polycarbonate - but the resultant polymers and their mixture can also be depolymerized back to the single, original monomer when facilitated by catalysis. Specifically, the lactone/epoxide hybrid bifunctional monomer (BiLO) undergoes ring-opening polymerization through the lactone manifold to produce polyester, PE(BiLO), and is also applied to ring-opening copolymerization with CO2, via the epoxide manifold, to yield polycarbonate, PC(BiLO). Remarkably, a one-pot recycling process of a BiLO-derived PE/PC blend back to the constituent monomer BiLO in >99 % selectivity was achieved with a superbase catalyst at 150 °C, thereby effectively obviating the requirement for sorting and separation typically required for recycling of mixed polymers.
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Affiliation(s)
- Changxia Shi
- Department of Chemistry, Colorado State University, Fort Collins, Colorado, 80523-1872, United States
| | - Wilfred T Diment
- Department of Chemistry, Colorado State University, Fort Collins, Colorado, 80523-1872, United States
| | - Eugene Y-X Chen
- Department of Chemistry, Colorado State University, Fort Collins, Colorado, 80523-1872, United States
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9
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Parkatzidis K, Wang HS, Anastasaki A. Photocatalytic Upcycling and Depolymerization of Vinyl Polymers. Angew Chem Int Ed Engl 2024; 63:e202402436. [PMID: 38466624 DOI: 10.1002/anie.202402436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/10/2024] [Accepted: 03/11/2024] [Indexed: 03/13/2024]
Abstract
Photocatalytic upcycling and depolymerization of vinyl polymers have emerged as promising strategies to combat plastic pollution and promote a circular economy. This mini review critically summarizes current developments in the upcycling and degradation of vinyl polymers including polystyrene and poly(meth)acrylates. Of these material classes, polymethacrylates possess the unique possibility to undergo a photocatalytic depolymerization back to monomer under thermodynamically favourable conditions, thus presenting significant advantages over traditional thermal strategies. Our perspective on current formidable challenges and potential future directions are also discussed.
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Affiliation(s)
- Kostas Parkatzidis
- Department of Materials Science, ETH Zurich, Vladimir-Prelog-Weg 5, 8093, Zürich, Switzerland
| | - Hyun Suk Wang
- Department of Materials Science, ETH Zurich, Vladimir-Prelog-Weg 5, 8093, Zürich, Switzerland
| | - Athina Anastasaki
- Department of Materials Science, ETH Zurich, Vladimir-Prelog-Weg 5, 8093, Zürich, Switzerland
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10
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Deng Y, Zhang Q, Feringa BL. Dynamic Chemistry Toolbox for Advanced Sustainable Materials. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2308666. [PMID: 38321810 PMCID: PMC11005721 DOI: 10.1002/advs.202308666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/28/2023] [Indexed: 02/08/2024]
Abstract
Developing dynamic chemistry for polymeric materials offers chemical solutions to solve key problems associated with current plastics. Mechanical performance and dynamic function are equally important in material design because the former determines the application scope and the latter enables chemical recycling and hence sustainability. However, it is a long-term challenge to balance the subtle trade-off between mechanical robustness and dynamic properties in a single material. The rise of dynamic chemistry, including supramolecular and dynamic covalent chemistry, provides many opportunities and versatile molecular tools for designing constitutionally dynamic materials that can adapt, repair, and recycle. Facing the growing social need for developing advanced sustainable materials without compromising properties, recent progress showing how the toolbox of dynamic chemistry can be explored to enable high-performance sustainable materials by molecular engineering strategies is discussed here. The state of the art and recent milestones are summarized and discussed, followed by an outlook toward future opportunities and challenges present in this field.
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Affiliation(s)
- Yuanxin Deng
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research CenterSchool of Chemistry and Technology130 Meilong RoadShanghai200237China
- Stratingh Institute for Chemistry and Zernike Institute for Advanced MaterialsFaculty of Science and EngineeringUniversity of GroningenNijenborgh 4Groningen9747 AGThe Netherlands
| | - Qi Zhang
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research CenterSchool of Chemistry and Technology130 Meilong RoadShanghai200237China
- Stratingh Institute for Chemistry and Zernike Institute for Advanced MaterialsFaculty of Science and EngineeringUniversity of GroningenNijenborgh 4Groningen9747 AGThe Netherlands
| | - Ben L. Feringa
- Key Laboratory for Advanced Materials and Feringa Nobel Prize Scientist Joint Research CenterSchool of Chemistry and Technology130 Meilong RoadShanghai200237China
- Stratingh Institute for Chemistry and Zernike Institute for Advanced MaterialsFaculty of Science and EngineeringUniversity of GroningenNijenborgh 4Groningen9747 AGThe Netherlands
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11
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Mountaki SA, Whitfield R, Parkatzidis K, Antonopoulou MN, Truong NP, Anastasaki A. Chemical recycling of bromine-terminated polymers synthesized by ATRP. RSC APPLIED POLYMERS 2024; 2:275-283. [PMID: 38525379 PMCID: PMC10955525 DOI: 10.1039/d3lp00279a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/11/2023] [Accepted: 01/25/2024] [Indexed: 03/26/2024]
Abstract
Chemical recycling of polymers is one of the biggest challenges in materials science. Recently, remarkable achievements have been made by utilizing polymers prepared by controlled radical polymerization to trigger low-temperature depolymerization. However, in the case of atom transfer radical polymerization (ATRP), depolymerization has nearly exclusively focused on chlorine-terminated polymers, even though the overwhelming majority of polymeric materials synthesized with this method possess a bromine end-group. Herein, we report an efficient depolymerization strategy for bromine-terminated polymethacrylates which employs an inexpensive and environmentally friendly iron catalyst (FeBr2/L). The effect of various solvents and the concentration of metal salt and ligand on the depolymerization are judiciously explored and optimized, allowing for a depolymerization efficiency of up to 86% to be achieved in just 3 minutes. Notably, the versatility of this depolymerization is exemplified by its compatibility with chlorinated and non-chlorinated solvents, and both Fe(ii) and Fe(iii) salts. This work significantly expands the scope of ATRP materials compatible with depolymerization and creates many future opportunities in applications where the depolymerization of bromine-terminated polymers is desired.
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Affiliation(s)
- Stella Afroditi Mountaki
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich Vladimir-Prelog-Weg-5 8093 Zurich Switzerland
| | - Richard Whitfield
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich Vladimir-Prelog-Weg-5 8093 Zurich Switzerland
| | - Kostas Parkatzidis
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich Vladimir-Prelog-Weg-5 8093 Zurich Switzerland
| | - Maria-Nefeli Antonopoulou
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich Vladimir-Prelog-Weg-5 8093 Zurich Switzerland
| | - Nghia P Truong
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich Vladimir-Prelog-Weg-5 8093 Zurich Switzerland
| | - Athina Anastasaki
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich Vladimir-Prelog-Weg-5 8093 Zurich Switzerland
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12
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Wimberger L, Ng G, Boyer C. Light-driven polymer recycling to monomers and small molecules. Nat Commun 2024; 15:2510. [PMID: 38509090 PMCID: PMC10954676 DOI: 10.1038/s41467-024-46656-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Accepted: 03/05/2024] [Indexed: 03/22/2024] Open
Abstract
Only a small proportion of global plastic waste is recycled, of which most is mechanically recycled into lower quality materials. The alternative, chemical recycling, enables renewed production of pristine materials, but generally comes at a high energy cost, particularly for processes like pyrolysis. This review focuses on light-driven approaches for chemically recycling and upcycling plastic waste, with emphasis on reduced energy consumption and selective transformations not achievable with heat-driven methods. We focus on challenging to recycle backbone structures composed of mainly C‒C bonds, which lack functional groups i.e., esters or amides, that facilitate chemical recycling e.g., by solvolysis. We discuss the use of light, either in conjunction with heat to drive depolymerization to monomers or via photocatalysis to transform polymers into valuable small molecules. The structural prerequisites for these approaches are outlined, highlighting their advantages as well as limitations. We conclude with an outlook, addressing key challenges, opportunities, and provide guidelines for future photocatalyst (PC) development.
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Affiliation(s)
- Laura Wimberger
- Cluster for Advanced Macromolecular Design and School of Chemical Engineering, The University of New South Wales, 2052, Sydney, NSW, Australia
| | - Gervase Ng
- Cluster for Advanced Macromolecular Design and School of Chemical Engineering, The University of New South Wales, 2052, Sydney, NSW, Australia
| | - Cyrille Boyer
- Cluster for Advanced Macromolecular Design and School of Chemical Engineering, The University of New South Wales, 2052, Sydney, NSW, Australia.
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13
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Zhang S, Li R, An Z. Degradable Block Copolymer Nanoparticles Synthesized by Polymerization-Induced Self-Assembly. Angew Chem Int Ed Engl 2024; 63:e202315849. [PMID: 38155097 DOI: 10.1002/anie.202315849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 12/20/2023] [Accepted: 12/28/2023] [Indexed: 12/30/2023]
Abstract
Polymerization-induced self-assembly (PISA) combines polymerization and in situ self-assembly of block copolymers in one system and has become a widely used method to prepare block copolymer nanoparticles at high concentrations. The persistence of polymers in the environment poses a huge threat to the ecosystem and represents a significant waste of resources. There is an urgent need to develop novel chemical approaches to synthesize degradable polymers. To meet with this demand, it is crucial to install degradability into PISA nanoparticles. Most recently, degradable PISA nanoparticles have been synthesized by introducing degradation mechanisms into either shell-forming or core-forming blocks. This Minireview summarizes the development in degradable block copolymer nanoparticles synthesized by PISA, including shell-degradable, core-degradable, and all-degradable nanoparticles. Future development will benefit from expansion of polymerization techniques with new degradation mechanisms and adaptation of high-throughput approaches for both PISA syntheses and degradation studies.
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Affiliation(s)
- Shudi Zhang
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Ruoyu Li
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Zesheng An
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun, 130012, China
- Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, School of Life Sciences, Jilin University, Changchun, 130012, China
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14
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Chin M, Yang T, Quirion KP, Lian C, Liu P, He J, Diao T. Implementing a Doping Approach for Poly(methyl methacrylate) Recycling in a Circular Economy. J Am Chem Soc 2024; 146:5786-5792. [PMID: 38382057 PMCID: PMC10921398 DOI: 10.1021/jacs.3c13223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 02/23/2024]
Abstract
To mitigate pollution by plastic waste, it is paramount to develop polymers with efficient recyclability while retaining desirable physical properties. A recyclable poly(methyl methacrylate) (PMMA) is synthesized by incorporating a minimal amount of an α-methylstyrene (AMS) analogue into the polymer structure. This P(MMA-co-AMS) copolymer preserves the essential mechanical strength and optical clarity of PMMA, vital for its wide-ranging applications in various commercial and high-tech industries. Doping with AMS significantly enhances the thermal, catalyst-free depolymerization efficiency of PMMA, facilitating the recovery of methyl methacrylate (MMA) with high yield and purity at temperatures ranging from 150 to 210 °C, nearly 250 K lower than current industrial standards. Furthermore, the low recovery temperature permits the isolation of pure MMA from a mixture of assorted common plastics.
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Affiliation(s)
- Mason
T. Chin
- Department
of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States
| | - Tiangang Yang
- Department
of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Kevin P. Quirion
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Christina Lian
- Department
of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States
| | - Peng Liu
- Department
of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States
| | - Jie He
- Department
of Chemistry, University of Connecticut, Storrs, Connecticut 06269, United States
| | - Tianning Diao
- Department
of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States
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15
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Ibrahim T, Ritacco A, Nalley D, Emon OF, Liang Y, Sun H. Chemical recycling of polyolefins via ring-closing metathesis depolymerization. Chem Commun (Camb) 2024; 60:1361-1371. [PMID: 38213307 DOI: 10.1039/d3cc05612k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2024]
Abstract
The current insufficient recycling of commodity polymer waste has resulted in pressing environmental and human health issues in our modern society. In the quest for next-generation polymer materials, chemists have recently shifted their attention to the design of chemically recyclable polymers that can undergo depolymerization to regenerate monomers under mild conditions. During the past decade, ring-closing metathesis reactions have been demonstrated to be a robust approach for the depolymerization of polyolefins, producing low-strain cyclic alkene products which can be repolymerized back to new batches of polymers. In this review, we aim to highlight the recent advances in chemical recycling of polyolefins enabled by ring-closing metathesis depolymerization (RCMD). A library of depolymerizable polyolefins will be covered based on the ring size of their monomers or depolymerization products, including five-membered, six-membered, eight-membered, and macrocyclic rings. Moreover, current limitations, potential applications, and future opportunities of the RCMD approach will be discussed. It is clear from recent research in this field that RCMD represents a powerful strategy towards closed-loop chemical recycling of novel polyolefin materials.
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Affiliation(s)
- Tarek Ibrahim
- Department of Chemistry and Chemical & Biomedical Engineering, Tagliatela College of Engineering, University of New Haven, West Haven, CT, 06516, USA.
| | - Angelo Ritacco
- Department of Chemistry and Chemical & Biomedical Engineering, Tagliatela College of Engineering, University of New Haven, West Haven, CT, 06516, USA.
| | - Daniel Nalley
- Department of Chemistry and Chemical & Biomedical Engineering, Tagliatela College of Engineering, University of New Haven, West Haven, CT, 06516, USA.
| | - Omar Faruk Emon
- Department of Mechanical and Industrial Engineering, Tagliatela College of Engineering, University of New Haven, West Haven, CT, 06516, USA
| | - Yifei Liang
- Department of Chemistry, Northwestern University, Evanston, Illinois 60208, USA
| | - Hao Sun
- Department of Chemistry and Chemical & Biomedical Engineering, Tagliatela College of Engineering, University of New Haven, West Haven, CT, 06516, USA.
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16
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Lohmann V, Jones GR, Truong NP, Anastasaki A. The thermodynamics and kinetics of depolymerization: what makes vinyl monomer regeneration feasible? Chem Sci 2024; 15:832-853. [PMID: 38239674 PMCID: PMC10793647 DOI: 10.1039/d3sc05143a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/28/2023] [Indexed: 01/22/2024] Open
Abstract
Depolymerization is potentially a highly advantageous method of recycling plastic waste which could move the world closer towards a truly circular polymer economy. However, depolymerization remains challenging for many polymers with all-carbon backbones. Fundamental understanding and consideration of both the kinetics and thermodynamics are essential in order to develop effective new depolymerization systems that could overcome this problem, as the feasibility of monomer generation can be drastically altered by tuning the reaction conditions. This perspective explores the underlying thermodynamics and kinetics governing radical depolymerization of addition polymers by revisiting pioneering work started in the mid-20th century and demonstrates its connection to exciting recent advances which report depolymerization reaching near-quantitative monomer regeneration at much lower temperatures than seen previously. Recent catalytic approaches to monomer regeneration are also explored, highlighting that this nascent chemistry could potentially revolutionize depolymerization-based polymer recycling in the future.
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Affiliation(s)
- Victoria Lohmann
- Laboratory of Polymeric Materials, Department of Materials, ETH Zürich Vladimir-Prelog-Weg 5 8093 Zürich Switzerland
| | - Glen R Jones
- Laboratory of Polymeric Materials, Department of Materials, ETH Zürich Vladimir-Prelog-Weg 5 8093 Zürich Switzerland
| | - Nghia P Truong
- Laboratory of Polymeric Materials, Department of Materials, ETH Zürich Vladimir-Prelog-Weg 5 8093 Zürich Switzerland
- Monash Institute of Pharmaceutical Sciences, Monash University 399 Royal Parade Parkville VIC 3152 Australia
| | - Athina Anastasaki
- Laboratory of Polymeric Materials, Department of Materials, ETH Zürich Vladimir-Prelog-Weg 5 8093 Zürich Switzerland
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17
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Ivanchenko O, Destarac M. 1,1'- Thiocarbonyldiimidazole Radical Copolymerization for the Preparation of Degradable Vinyl Polymers. ACS Macro Lett 2024; 13:47-51. [PMID: 38118079 DOI: 10.1021/acsmacrolett.3c00676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
1,1'-Thiocarbonyldiimidazole (TCDI) readily undergoes radical copolymerization with tert-butyl acrylate (tBA), N,N-dimethylacrylamide, and styrene. 1H NMR monitoring of the comonomer reactivity revealed a notable compatibility between TCDI and comonomers, resulting in similar consumption rates when TCDI was introduced at a 10% feed ratio. Furthermore, trithiocarbonate-mediated RAFT copolymerization of TCDI with tBA gave polymers that exhibited a linear increase of molar mass (Mnth = 2-10 kg mol-1) with conversion with relatively low dispersities (1.2-1.4). Importantly, this process enabled a successful chain extension of the produced P(TCDI-co-tBA) copolymer with styrene to form a diblock copolymer. The copolymers generated through this method contain TCDI-derived diimidazolyl thioether moieties, as established through 1H NMR spectroscopy. Additionally, degradation experiments using isopropylamine, benzoyl peroxide, sodium methoxide, and bleach have provided further confirmation of the presence of degradable TCDI moieties in the vinyl copolymer backbone.
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Affiliation(s)
- Oleksandr Ivanchenko
- Laboratoire SOFTMAT, Université de Toulouse, CNRS UMR 5623, Université Toulouse III-Paul Sabatier, Toulouse 31062, France
| | - Mathias Destarac
- Laboratoire SOFTMAT, Université de Toulouse, CNRS UMR 5623, Université Toulouse III-Paul Sabatier, Toulouse 31062, France
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18
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Mineo AM, Katsumata R. A Versatile Comonomer Additive for Radically Recyclable Vinyl-derived Polymers. Angew Chem Int Ed Engl 2024; 63:e202316248. [PMID: 38029360 DOI: 10.1002/anie.202316248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/01/2023]
Abstract
Radically-formed, vinyl-derived polymers account for over 30 % of polymer production. Connected through stable carbon-carbon bonds, these materials are notoriously challenging to chemically recycle. Herein, we report universal copolymerization of a cyclic allyl sulfide (CAS) additive with multiple monomers under free-radical conditions, to introduce main-chain dynamic motifs. Backbone allyl sulfides undergo post-polymerization radical rearrangement via addition-fragmentation-transfer (AFT) that fosters both chain scission and extension. Scission is selectively induced through allyl sulfide exchange with small molecule thiyl radicals, resulting in oligomers as low as 14 % of the initial molar mass. Crucially, oligomers retain allyl sulfide end groups, enabling their extension with monomer under radical conditions. Extended, i.e., recycled, product molar mass is tunable through the ratio of monomer to oligomer, and can surpass that of the initial copolymer. Two scission-extension cycles are demonstrated in copolymers with methyl methacrylate and styrene without escalation in dispersity. In illustration of forming higher-value products, i.e., upcycling, we synthesized block copolymers through the extension of oligomers with a different vinyl monomer. Collectively, our approach to chemical recycling is unparalleled in its ability to 1) function in a variety of vinyl-derived polymers, 2) complete radical closed-loop cycling, and 3) upcycle waste material.
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Affiliation(s)
- Autumn M Mineo
- Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA
| | - Reika Katsumata
- Department of Polymer Science and Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA
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19
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Kuroda K, Ouchi M. Umpolung Isomerization in Radical Copolymerization of Benzyl Vinyl Ether with Pentafluorophenylacrylate Leading to Degradable AAB Periodic Copolymers. Angew Chem Int Ed Engl 2024; 63:e202316875. [PMID: 37971837 DOI: 10.1002/anie.202316875] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 11/16/2023] [Accepted: 11/16/2023] [Indexed: 11/19/2023]
Abstract
This study revealed that benzyl vinyl ether (BnVE) shows a peculiar isomerization propagation in its radical copolymerization with an electron-deficient acrylate carrying a pentafluorophenyl group (PFA). The co-monomer pair inherently exhibits the cross-over propagation feature due to the large difference in the electron density. However, the radical species of PFA was found to undergo a backward isomerization to the penultimate BnVE pendant giving a benzyl radical species prior to propagation with BnVE. The isomerization brings a drastic change in the character of the growing radical species from electrophilic to nucleophilic, and thus the isomerized benzyl radial species propagates with PFA. Consequently, the two monomers were consumed in the order AAB (A: PFA; B: BnVE) and the unique periodic consumption was confirmed by the pseudo-reactivity ratios calculated by the penultimate model: r11 =0.174 and r21 =6600 for PFA (M1 ) with BnVE (M2 ). The pentafluorophenyl ester groups of the resulting copolymers are transformed into ester and amide groups by post-polymerization alcoholysis and aminolysis modifications. The unique isomerization in the AAB sequence allowed the periodic introduction of a benzyl ether structure in the backbone leading to efficient degradation under acid conditions.
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Affiliation(s)
- Keita Kuroda
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
| | - Makoto Ouchi
- Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University, Nishikyo-ku, Kyoto, 615-8510, Japan
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20
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Hou Y, Zhu G, Catt SO, Yin Y, Xu J, Blasco E, Zhao N. Closed-Loop Recyclable Silica-Based Nanocomposites with Multifunctional Properties and Versatile Processability. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2304147. [PMID: 37844996 PMCID: PMC10724396 DOI: 10.1002/advs.202304147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 08/06/2023] [Indexed: 10/18/2023]
Abstract
Most plastics originate from limited petroleum reserves and cannot be effectively recycled at the end of their life cycle, making them a significant threat to the environment and human health. Closed-loop chemical recycling, by depolymerizing plastics into monomers that can be repolymerized, offers a promising solution for recycling otherwise wasted plastics. However, most current chemically recyclable polymers may only be prepared at the gram scale, and their depolymerization typically requires harsh conditions and high energy consumption. Herein, it reports less petroleum-dependent closed-loop recyclable silica-based nanocomposites that can be prepared on a large scale and have a fully reversible polymerization/depolymerization capability at room temperature, based on catalysis of free aminopropyl groups with the assistance of diethylamine or ethylenediamine. The nanocomposites show glass-like hardness yet plastic-like light weight and toughness, exhibiting the highest specific mechanical strength superior even to common materials such as poly(methyl methacrylate), glass, and ZrO2 ceramic, as well as demonstrating multifunctionality such as anti-fouling, low thermal conductivity, and flame retardancy. Meanwhile, these nanocomposites can be easily processed by various plastic-like scalable manufacturing methods, such as compression molding and 3D printing. These nanocomposites are expected to provide an alternative to petroleum-based plastics and contribute to a closed-loop materials economy.
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Affiliation(s)
- Yi Hou
- Beijing National Laboratory for Molecular SciencesLaboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM)Heidelberg University69120HeidelbergGermany
- Organic Chemistry Institute (OCI)Heidelberg University69120HeidelbergGermany
| | - Guangda Zhu
- Beijing National Laboratory for Molecular SciencesLaboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM)Heidelberg University69120HeidelbergGermany
- Organic Chemistry Institute (OCI)Heidelberg University69120HeidelbergGermany
| | - Samantha O. Catt
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM)Heidelberg University69120HeidelbergGermany
- Organic Chemistry Institute (OCI)Heidelberg University69120HeidelbergGermany
| | - Yuhan Yin
- Beijing National Laboratory for Molecular SciencesLaboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
| | - Jian Xu
- Beijing National Laboratory for Molecular SciencesLaboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
| | - Eva Blasco
- Institute for Molecular Systems Engineering and Advanced Materials (IMSEAM)Heidelberg University69120HeidelbergGermany
- Organic Chemistry Institute (OCI)Heidelberg University69120HeidelbergGermany
| | - Ning Zhao
- Beijing National Laboratory for Molecular SciencesLaboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190P. R. China
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21
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Zhao R, Wang C, Huang K, Li L, Fan W, Zhu Q, Ma H, Wang X, Wang Z, Huang W. Macromolecular Engineered Multifunctional Room-Temperature Phosphorescent Polymers through Reversible Deactivation Radical Polymerization. J Am Chem Soc 2023. [PMID: 38035385 DOI: 10.1021/jacs.3c10673] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
Despite the intensive research in room-temperature phosphorescent (RTP) polymers, the synthesis of RTP polymers with well-defined macromolecular structures and multiple functions remains a challenge. Herein, reversible deactivation radical polymerization was demonstrated to offer a gradient copolymer (GCP) architecture with controlled heterogeneities, which combines hard segment and flexible segment. The GCPs would self-assemble into a multiphase nanostructure, featuring tunable stretchability, excellent RTP performance, and intrinsic healability without compromising light emission under stretching. The mechanical performance is tunable on demand with elongation at break ranging from 5.0% to 221.7% and Young's modulus ranging from 0.5 to 225.0 MPa.
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Affiliation(s)
- Ruoqing Zhao
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
| | - Chen Wang
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
| | - Keer Huang
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
| | - Lei Li
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
| | - Wenru Fan
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
| | - Qixuan Zhu
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
| | - Huihui Ma
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
| | - Xuewen Wang
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
| | - Zhenhua Wang
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
| | - Wei Huang
- Frontiers Science Center for Flexible Electronics (FSCFE) & Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University, Xi'an 710072, China
- State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM), Nanjing University of Posts & Telecommunications, 9 Wenyuan Road, Nanjing 210023, China
- Key Laboratory of Flexible Electronics (KLoFE) and Institute of Advanced Materials (IAM), Nanjing Tech University (NanjingTech), 30 South Puzhu Road, Nanjing 211816, China
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22
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Bellotti V, Wang HS, Truong NP, Simonutti R, Anastasaki A. Temporal Regulation of PET-RAFT Controlled Radical Depolymerization. Angew Chem Int Ed Engl 2023; 62:e202313232. [PMID: 37814385 DOI: 10.1002/anie.202313232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Indexed: 10/11/2023]
Abstract
A photocatalytic RAFT-controlled radical depolymerization method is introduced for precisely conferring temporal control under visible light irradiation. By regulating the deactivation of the depropagating chains and suppressing thermal initiation, an excellent temporal control was enabled, exemplified by several consecutive "on" and "off" cycles. Minimal, if any, depolymerization could be observed during the dark periods while the polymer chain-ends could be efficiently re-activated and continue to depropagate upon re-exposure to light. Notably, favoring deactivation resulted in the gradual unzipping of polymer chains and a stepwise decrease in molecular weight over time. This synthetic approach constitutes a simple methodology to modulate temporal control during the chemical recycling of RAFT-synthesized polymers while offering invaluable mechanistic insights.
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Affiliation(s)
- Valentina Bellotti
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg-5, Zurich, 8093, Switzerland
- Department of Material Science, Università di Milano-Bicocca, Via Roberto Cozzi 55, Milan, 20125, Italy
| | - Hyun Suk Wang
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg-5, Zurich, 8093, Switzerland
| | - Nghia P Truong
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg-5, Zurich, 8093, Switzerland
| | - Roberto Simonutti
- Department of Material Science, Università di Milano-Bicocca, Via Roberto Cozzi 55, Milan, 20125, Italy
| | - Athina Anastasaki
- Laboratory of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg-5, Zurich, 8093, Switzerland
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23
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Parkatzidis K, Truong NP, Matyjaszewski K, Anastasaki A. Photocatalytic ATRP Depolymerization: Temporal Control at Low ppm of Catalyst Concentration. J Am Chem Soc 2023; 145:21146-21151. [PMID: 37737835 PMCID: PMC10557129 DOI: 10.1021/jacs.3c05632] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Indexed: 09/23/2023]
Abstract
A photocatalytic ATRP depolymerization is introduced that significantly suppresses the reaction temperature from 170 to 100 °C while enabling temporal regulation. In the presence of low-toxicity iron-based catalysts and under visible light irradiation, near-quantitative monomer recovery could be achieved (up to 90%), albeit with minimal temporal control. By employing ppm concentrations of either FeCl2 or FeCl3, the depolymerization during the dark periods could be completely eliminated, thus enabling temporal control and the possibility to modulate the rate by simply turning the light "on" and "off". Notably, our approach allowed preservation of the end-group fidelity throughout the reaction, could be carried out at high polymer loadings (up to 2M), and was compatible with various polymers and light sources. This methodology provides a facile, environmentally friendly, and temporally regulated route to chemically recycle ATRP-synthesized polymers, thus opening the door for further opportunities.
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Affiliation(s)
- Kostas Parkatzidis
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich 8093, Switzerland
| | - Nghia P. Truong
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich 8093, Switzerland
| | - Krzysztof Matyjaszewski
- Department
of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Athina Anastasaki
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, Zurich 8093, Switzerland
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24
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Deng Z, Gillies ER. Emerging Trends in the Chemistry of End-to-End Depolymerization. JACS AU 2023; 3:2436-2450. [PMID: 37772181 PMCID: PMC10523501 DOI: 10.1021/jacsau.3c00345] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/09/2023] [Accepted: 08/16/2023] [Indexed: 09/30/2023]
Abstract
Over the past couple of decades, polymers that depolymerize end-to-end upon cleavage of their backbone or activation of a terminal functional group, sometimes referred to as "self-immolative" polymers, have been attracting increasing attention. They are of growing interest in the context of enhancing polymer degradability but also in polymer recycling as they allow monomers to be regenerated in a controlled manner under mild conditions. Furthermore, they are highly promising for applications as smart materials due to their ability to provide an amplified response to a specific signal, as a single sensing event is translated into the generation of many small molecules through a cascade of reactions. From a chemistry perspective, end-to-end depolymerization relies on the principles of self-immolative linkers and polymer ceiling temperature (Tc). In this article, we will introduce the key chemical concepts and foundations of the field and then provide our perspective on recent exciting developments. For example, over the past few years, new depolymerizable backbones, including polyacetals, polydisulfides, polyesters, polythioesters, and polyalkenamers, have been developed, while modern approaches to depolymerize conventional backbones such as polymethacrylates have also been introduced. Progress has also been made on the topological evolution of depolymerizable systems, including the introduction of fully depolymerizable block copolymers, hyperbranched polymers, and polymer networks. Furthermore, precision sequence-defined oligomers have been synthesized and studied for data storage and encryption. Finally, our perspectives on future opportunities and challenges in the field will be discussed.
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Affiliation(s)
- Zhengyu Deng
- Department
of Chemistry, The University of Western
Ontario, 1151 Richmond St., London, Ontario N6A 5B7, Canada
| | - Elizabeth R. Gillies
- Department
of Chemistry, The University of Western
Ontario, 1151 Richmond St., London, Ontario N6A 5B7, Canada
- Department
of Chemical and Biochemical Engineering, The University of Western Ontario, 1151 Richmond St., London, Ontario N6A 5B9, Canada
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25
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Häfliger F, Truong NP, Wang HS, Anastasaki A. Fate of the RAFT End-Group in the Thermal Depolymerization of Polymethacrylates. ACS Macro Lett 2023; 12:1207-1212. [PMID: 37615956 PMCID: PMC10515620 DOI: 10.1021/acsmacrolett.3c00418] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 08/21/2023] [Indexed: 08/25/2023]
Abstract
Thermal RAFT depolymerization has recently emerged as a promising methodology for the chemical recycling of polymers. However, while much attention has been given to the regeneration of monomers, the fate of the RAFT end-group after depolymerization has been unexplored. Herein, we identify the dominant small molecules derived from the RAFT end-group of polymethacrylates. The major product was found to be a unimer (DP = 1) RAFT agent, which is not only challenging to synthesize using conventional single-unit monomer insertion strategies, but also a highly active RAFT agent for methyl methacrylate, exhibiting faster consumption and yielding polymers with lower dispersities compared to the original, commercially available 2-cyano-2-propyl dithiobenzoate. Solvent-derived molecules were also identified predominantly at the beginning of the depolymerization, thus suggesting a significant mechanistic contribution from the solvent. Notably, the formation of both the unimer and the solvent-derived products remained consistent regardless of the RAFT agent, monomer, or solvent employed.
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Affiliation(s)
- Florian Häfliger
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
| | - Nghia P. Truong
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
- Monash
Institute of Pharmaceutical Sciences, Monash
University, 399 Royal
Parade, Parkville, VIC 3152, Australia
| | - Hyun Suk Wang
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
| | - Athina Anastasaki
- Laboratory
of Polymeric Materials, Department of Materials, ETH Zurich, Vladimir-Prelog-Weg 5, 8093 Zurich, Switzerland
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26
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Whitfield R, Jones GR, Truong NP, Manring LE, Anastasaki A. Solvent-Free Chemical Recycling of Polymethacrylates made by ATRP and RAFT polymerization: High-Yielding Depolymerization at Low Temperatures. Angew Chem Int Ed Engl 2023; 62:e202309116. [PMID: 37523176 DOI: 10.1002/anie.202309116] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 07/31/2023] [Accepted: 07/31/2023] [Indexed: 08/01/2023]
Abstract
Although controlled radical polymerization is an excellent tool to make precision polymeric materials, reversal of the process to retrieve the starting monomer is far less explored despite the significance of chemical recycling. Here, we investigate the bulk depolymerization of RAFT and ATRP-synthesized polymers under identical conditions. RAFT-synthesized polymers undergo a relatively low-temperature solvent-free depolymerization back to monomer thanks to the partial in situ transformation of the RAFT end-group to macromonomer. Instead, ATRP-synthesized polymers can only depolymerize at significantly higher temperatures (>350 °C) through random backbone scission. To aid a more complete depolymerization at even lower temperatures, we performed a facile and quantitative end-group modification strategy in which both ATRP and RAFT end-groups were successfully converted to macromonomers. The macromonomers triggered a lower temperature bulk depolymerization with an onset at 150 °C yielding up to 90 % of monomer regeneration. The versatility of the methodology was demonstrated by a scalable depolymerization (≈10 g of starting polymer) retrieving 84 % of the starting monomer intact which could be subsequently used for further polymerization. This work presents a new low-energy approach for depolymerizing controlled radical polymers and creates many future opportunities as high-yielding, solvent-free and scalable depolymerization methods are sought.
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Affiliation(s)
- Richard Whitfield
- Laboratory of Polymeric Materials, D-MATL, ETH Zurich, Vladimir-Prelog-Weg-5, 8093, Zurich, Switzerland
| | - Glen R Jones
- Laboratory of Polymeric Materials, D-MATL, ETH Zurich, Vladimir-Prelog-Weg-5, 8093, Zurich, Switzerland
| | - Nghia P Truong
- Laboratory of Polymeric Materials, D-MATL, ETH Zurich, Vladimir-Prelog-Weg-5, 8093, Zurich, Switzerland
| | | | - Athina Anastasaki
- Laboratory of Polymeric Materials, D-MATL, ETH Zurich, Vladimir-Prelog-Weg-5, 8093, Zurich, Switzerland
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27
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Nifant’ev IE, Korchagina SA, Chinova MS, Tavtorkin AN. Polyisobutylenes with Controlled Molecular Weight and Chain-End Structure: Synthesis and Actual Applications. Polymers (Basel) 2023; 15:3415. [PMID: 37631472 PMCID: PMC10460079 DOI: 10.3390/polym15163415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/05/2023] [Accepted: 08/09/2023] [Indexed: 08/27/2023] Open
Abstract
The polymerization of isobutylene allows us to obtain a wide spectrum of polyisobutylenes (PIBs) which differ in their molecular weight characteristics and the chemical structure of chain-end groups. The bulk of the PIBs manufactured worldwide are highly reactive polyisobutylenes (HRPIBs) with -C(Me)=CH2 end-groups and low-molecular weights (Mn < 5 kDa). HRPIBs are feedstocks that are in high demand in the manufacturing of additives for fuels and oils, adhesives, detergents, and other fine chemicals. In addition, HRPIBs and CMe2Cl-terminated PIBs are intensively studied with the aim of finding biomedical applications and for the purpose of developing new materials. Both chain control (molecular weight and dispersity) and chemoselectivity (formation of exo-olefinic or -CMe2Cl groups) should be achieved during polymerization. This review highlights the fundamental issues in the mechanisms of isobutylene polymerization and PIB analysis, examines actual catalytic approaches to PIBs, and describes recent studies on the functionalization and applications of HRPIBs and halogen-terminated PIBs.
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Affiliation(s)
- Ilya E. Nifant’ev
- A.V. Topchiev Institute of Petrochemical Synthesis RAS, 29 Leninsky Pr., 119991 Moscow, Russia; (S.A.K.); (M.S.C.); (A.N.T.)
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De Luca
Bossa F, Yilmaz G, Matyjaszewski K. Fast Bulk Depolymerization of Polymethacrylates by ATRP. ACS Macro Lett 2023; 12:1173-1178. [PMID: 37531639 PMCID: PMC10433507 DOI: 10.1021/acsmacrolett.3c00389] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 07/28/2023] [Indexed: 08/04/2023]
Abstract
Fast bulk depolymerization of poly(n-butyl methacrylate) and poly(methyl methacrylate), prepared by atom transfer radical polymerization (ATRP), is reported in the temperature range between 150 and 230 °C. Depolymerization of Cl-terminated polymethacrylates was catalyzed by a CuCl2/TPMA complex (0.022 or 0.22 equiv vs P-Cl) and was studied using TGA, also under isothermal conditions. Relatively rapid 5-20 min depolymerization was observed at 230 and 180 °C. The preparative scale reactions were carried out using a short-path distillation setup with up to 84% depolymerization within 15 min at 230 °C.
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Affiliation(s)
- Ferdinando De Luca
Bossa
- Department
of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Gorkem Yilmaz
- Department
of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
| | - Krzysztof Matyjaszewski
- Department
of Chemistry, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh, Pennsylvania 15213, United States
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