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Pal A, Wong AR, Lamb JR. Chemically Recyclable, High Molar Mass Polyoxazolidinones via Ring-Opening Metathesis Polymerization. ACS Macro Lett 2024; 13:502-507. [PMID: 38625148 DOI: 10.1021/acsmacrolett.4c00147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
The development of robust methods for the synthesis of chemically recyclable polymers with tunable properties is necessary for the design of next-generation materials. Polyoxazolidinones (POxa), polymers with five-membered urethanes in their backbones, are an attractive target because they are strongly polar and have high thermal stability, but existing step-growth syntheses limit molar masses and methods to chemically recycle POxa to monomer are rare. Herein, we report the synthesis of high molar mass POxa via ring-opening metathesis polymerization of oxazolidinone-fused cyclooctenes. These novel polymers show <5% mass loss up to 382-411 °C and have tunable glass transition temperatures (14-48 °C) controlled by the side chain structure. We demonstrate facile chemical recycling to monomer and repolymerization despite moderately high monomer ring-strain energies, which we hypothesize are facilitated by the conformational restriction introduced by the fused oxazolidinone ring. This method represents the first chain growth synthesis of POxa and provides a versatile platform for the study and application of this emerging subclass of polyurethanes.
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Affiliation(s)
- Arpan Pal
- Department of Chemistry, University of Minnesota-Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Allison R Wong
- Department of Chemistry, University of Minnesota-Twin Cities, Minneapolis, Minnesota 55455, United States
| | - Jessica R Lamb
- Department of Chemistry, University of Minnesota-Twin Cities, Minneapolis, Minnesota 55455, United States
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Shi JX, Ciccia NR, Pal S, Kim DD, Brunn JN, Lizandara-Pueyo C, Ernst M, Haydl AM, Messersmith PB, Helms BA, Hartwig JF. Chemical Modification of Oxidized Polyethylene Enables Access to Functional Polyethylenes with Greater Reuse. J Am Chem Soc 2023; 145:21527-21537. [PMID: 37733607 DOI: 10.1021/jacs.3c07186] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/23/2023]
Abstract
Polyethylene is a commodity material that is widely used because of its low cost and valuable properties. However, the lack of functional groups in polyethylene limits its use in applications that include adhesives, gas barriers, and plastic blends. The inertness of polyethylene makes it difficult to install groups that would enhance its properties and enable programmed chemical decomposition. To overcome these deficiencies, the installation of pendent functional groups that imbue polyethylene with enhanced properties is an attractive strategy to overcome its inherent limitations. Here, we describe strategies to derivatize oxidized polyethylene that contains both ketones and alcohols to monofunctional variants with bulk properties superior to those of unmodified polyethylene. Iridium-catalyzed transfer dehydrogenation with acetone furnished polyethylenes with only ketones, and ruthenium-catalyzed hydrogenation with hydrogen furnished polyethylenes with only alcohols. We demonstrate that the ratio of these functional groups can be controlled by reduction with stoichiometric hydride-containing reagents. The ketones and alcohols serve as sites to introduce esters and oximes onto the polymer, thereby improving surface and bulk properties over those of polyethylene. These esters and oximes were removed by hydrolysis to regenerate the original oxygenated polyethylenes, showing how functionalization can lead to materials with circularity. Waste polyethylenes were equally amenable to oxidative functionalization and derivatization of the oxidized material, showing that this low- or negative-value feedstock can be used to prepare materials of higher value. Finally, the derivatized polymers with distinct solubilities were separated from mechanically mixed plastic blends by selective dissolution, demonstrating that functionalization can lead to novel approaches for distinguishing and separating polymers from a mixture.
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Affiliation(s)
- Jake X Shi
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Nicodemo R Ciccia
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Subhajit Pal
- Department of Materials Science and Bioengineering, University of California, Berkeley, California 94720, United States
| | - Diane D Kim
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - John N Brunn
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | | | | | | | - Phillip B Messersmith
- Department of Materials Science and Bioengineering, University of California, Berkeley, California 94720, United States
| | - Brett A Helms
- The Molecular Foundry and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - John F Hartwig
- Department of Chemistry, University of California, Berkeley, California 94720, United States
- Division of Chemical Sciences, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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Wang T, Zhang Y, Wang Y, You W. Transition-metal-free preparation of polyethylene-based anion exchange membranes from commercial EVA. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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