Upgrading polyolefin plastics: experiences from petroleum refining and distinct characteristics

Science China Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 19, 2025

Language: Английский

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Nitrogenative Degradation of Polystyrene Waste

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 8, 2025

Owing to massive production and poor end-of-life management, plastic waste pollution has become one of the most pressing environmental crises. In response mounting crisis, past several decades have witnessed development numerous methods technologies for recycling. However, current recycling often produce low-quality or low-value products, making it difficult recover operating costs. To this end, we report a novel preoxygenation-induced strategy nitrogenative degradation real-life polystyrene plastics into high-value aromatic nitrogen compounds in cost-effective manner. Thus, expensive highly demanding benzonitrile as well benzamide were obtained up 74% overall isolated yield from by using CuBr catalyst, O2 oxidant, CH3CN source. Detailed mechanistic investigations indicate that hydroxyl radicals activation play role selective aerobic process. Furthermore, multiple reaction pathways contribute formation benzamide.

Language: Английский

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Selective Liquid Chemical Production in Waste Polyolefin Photorefinery by Controlling Reactive Species

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

Photocatalytic upcycling of waste polyolefins into value-added chemicals provides promise in plastic management and resource utilization. Previous works demonstrate that can be converted carboxylic acids, with CO2 as the final oxidation product. It is still challenging to explore more transformation products, particularly mild-oxidation products such alcohols, because their instability compared polymer substrates, which are prone during catalytic reactions. In this work, we propose an efficient strategy regulate product type through precise control radicals, intermediates, reaction paths. Taking commonly used photocatalyst C3N4 example, its major acids CO2. When MoS2 introduced construct a Z-scheme heterostructure, gas significantly reduced alcohols appear high yield 1358.8 μmol gcat-1 selectivity up 80.3%. This primarily attributed presence •OH radicals from oxygen reduction, acting key role alcohol formation while simultaneously suppressing competing pathways •O2- 1O2, thus reducing overoxidation products. The β-scission C-C bonds chains generates intermediate alkyl species, followed by combination produce methanol, energetically favorable for MoS2/C3N4. contrast, species couple form formic acid, C3N4. work new approaches controlling types offers insights involved polyolefin photorefinery.

Language: Английский

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Photochemical upcycling of polymers via visible light-driven C−H bond activation

Chemical Communications, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

This mini-review highlights the scientific breakthroughs in photochemical upcycling polymers through oxidative degradation and post-polymerization modification via visible light-driven C–H bond activation.

Language: Английский

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Synthesis of Polyamides Bearing Directing Groups and Their Catalytic Depolymerization

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 31, 2025

We report a directing group (DG)-enabled strategy for polyamide depolymerization. Pyridine-based DGs selectively interact with In(III) catalysts, activating amide bonds catalytic cleavage via alcoholysis. The process achieves efficient depolymerization of DG-introduced polyamides into recyclable monomers, providing sustainable chemical recycling approach robust polyamides.

Language: Английский

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Accessing a Carboxyl‐Anhydride Molecular Switch‐Mediated Recyclable PECT Through Upcycling End‐of‐Use PET

Angewandte Chemie International Edition, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 6, 2025

Poly(ethylene terephthalate) (PET), with an annual production of exceeding 70 million tons, is mainly utilized in disposable fields and subsequently contribute to severe environmental pollution. Conventional chemical recycling, which typically involves depolymerizing polymer into monomers, limited due the intricate recycling process, excess using unrecyclable solvents low conversion. Inspired by protein's molecular switches, we propose a novel polymer-to-polymer strategy based on polycondensation principles upcycling waste PET high-value recyclable poly(ethylene-co-1,4-cyclohexanedimethanol derivatives containing switches. Upon deactivating switch, acidification reaction occurs within system, leading rapid controllable reduction weight imbalance reactive group. Conversely, activating switch triggers ring-closing that detaches acid anhydrides, bringing about equal molar ratio groups thereby facilitating increase weight. By simply incorporating condensation products melt polycondensation, closed-loop capability achieved without necessitating excessive organic or complex depolymerization processes. The present study not only presents pathway for end-of-use but also introduces innovative concept switching recyclability polymers, demonstrating significant potential large-scale implementation.

Language: Английский

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Accessing a Carboxyl‐Anhydride Molecular Switch‐Mediated Recyclable PECT Through Upcycling End‐of‐Use PET

Angewandte Chemie, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 6, 2025

Abstract Poly(ethylene terephthalate) (PET), with an annual production of exceeding 70 million tons, is mainly utilized in disposable fields and subsequently contribute to severe environmental pollution. Conventional chemical recycling, which typically involves depolymerizing polymer into monomers, limited due the intricate recycling process, excess using unrecyclable solvents low conversion. Inspired by protein's molecular switches, we propose a novel polymer‐to‐polymer strategy based on polycondensation principles upcycling waste PET high‐value recyclable poly(ethylene‐ co ‐1,4‐cyclohexanedimethanol derivatives containing switches. Upon deactivating switch, acidification reaction occurs within system, leading rapid controllable reduction weight imbalance reactive group. Conversely, activating switch triggers ring‐closing that detaches acid anhydrides, bringing about equal molar ratio groups thereby facilitating increase weight. By simply incorporating condensation products melt polycondensation, closed‐loop capability achieved without necessitating excessive organic or complex depolymerization processes. The present study not only presents pathway for end‐of‐use but also introduces innovative concept switching recyclability polymers, demonstrating significant potential large‐scale implementation.

Language: Английский

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Upcycling of Waste Plastics into Value-Added Chemicals

Science for energy and environment., Journal Year: 2025, Volume and Issue: unknown, P. 4 - 4

Published: March 27, 2025

Review Upcycling of Waste Plastics into Value-Added Chemicals Jin Xu and Jing Zhang * State Key Laboratory Chemical Engineering, East China University Science Technology, 130 Meilong Road, Shanghai 200237, Correspondence: [email protected] Received: 8 November 2024; Revised: 22 January 2025; Accepted: 24 March Published: 27 2025 Abstract: The rapid increase in plastic production has led to a severe waste crisis, driving the development various recycling technologies mitigate this growing issue. However, these often encounter substantial economic environmental challenges their implementation. An increasingly attractive alternative is chemical upcycling, which can transform plastics value-added chemicals. This review systematically examines upcycling applicable major commercial plastics, including polyethylene terephthalate (PET), polyolefins, polystyrene (PS), polyvinyl chloride (PVC). We focus on key strategies such as solvolysis, catalytic pyrolysis, hydrocracking hydrogenolysis, along with some emerging approaches electrocatalysis photooxidation, aiming summarize trends plastics.

Language: Английский

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Highly adaptable oxidative upcycling of polyolefins to multifunctional chemicals containing oxygen and nitrogen

Materials Horizons, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

Highly adaptable upcycling of waste polyolefins was demonstrated to obtain high-value nitro-containing polycarboxylic acids in high carbon yields.

Language: Английский

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Electrochemical Commodity Polymer Up‐ and Re‐Cycling: Toward Sustainable and Circular Plastic Treatment

Macromolecular Rapid Communications, Journal Year: 2025, Volume and Issue: unknown

Published: April 18, 2025

Abstract The demand for commodity plastics reaches unprecedented dimensions. In contrast to the well‐developed plethora of methods polymer synthesis, sustainable strategies end‐of‐life management continue be scarce. While mechanical re‐cycling often results in downgraded materials, chemical or up‐cycling offers tremendous potential an efficient and green approach, thereby addressing precarious treatment post‐use within a circular carbon economy. Recently, electrochemistry surfaced as uniquely powerful tool via functionalization degradation obtaining either novel polymers with valorized properties high‐value recycled small molecules, respectively. discussing recent progress that domain, future perspectives electrochemical modifications until January 2025 are outlined herein.

Language: Английский

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