Chemical Communications, Год журнала: 2024, Номер 60(93), С. 13714 - 13717
Опубликована: Янв. 1, 2024
The degradation mechanisms of poly(7-oxa-2,3-diazanorbornene), which is a backbone-degradable polymer produced by living ring-opening metathesis polymerization, under both acidic and neutral pH environments are elucidated.
Язык: Английский
Journal of the American Chemical Society, Год журнала: 2025, Номер unknown
Опубликована: Янв. 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.
Язык: Английский
Процитировано
3
Journal of the American Chemical Society, Год журнала: 2025, Номер unknown
Опубликована: Янв. 27, 2025
Enthalpy is often the focal point when designing monomers for polymer circularity, but much less explored on how entropy can be exploited to create polymers with synergistic circularity and properties. Here, we design a series of spiro-lactones (SLs) closed-chain cycloalk(en)yl substituents at α,α-position δ-valerolactone (δVL), which, combined parent δVL gem-α,α-dialkyl-substituted open-chain alkyl groups, provide desired platform exploring circular by focusing change polymerization. These SLs exhibit finely balanced (de)polymerizability that regulated chiefly differentiation, allowing both facile synthesis polyester PSLs (Mn up 1000 kg mol–1) in living fashion selective depolymerization completely recover under mild conditions (using recyclable catalyst 100 °C). One such PSL semicrystalline (Tm = 134 °C), strong (ultimate strength 43 MPa), hard (modulus 1.85 GPa), modestly flexible. notable mechanical properties are bolstered its superior barriers oxygen moisture permeation compared common packaging materials. In addition, this postfunctionalized OH-containing shows higher adhesion than comparative commercial adhesives.
Язык: Английский
Процитировано
2
Macromolecules, Год журнала: 2025, Номер 58(5), С. 2210 - 2223
Опубликована: Фев. 18, 2025
Polymeric materials have become indispensable due to their versatility and low cost, yet environmental impact presents a significant global challenge. Traditional chemical recycling methods typically rely on heat as stimulus; for instance, pyrolysis is popular methodology which faces limitations high energy consumption, product selectivity, the generation of undesirable byproducts. In response, recent advances in promotion depolymerization degradation through alternative stimuli such light, electrochemistry, mechanical force, shown promising potential more efficient selective polymer breakdown, yielding either starting monomers or valuable small molecules. This perspective explores key examples these emerging strategies, highlighting improve upon current protocols offer pathways under milder conditions, while identifying challenges that future research must address translate chemistry into viable broadly applicable strategies.
Язык: Английский
Процитировано
2
Journal of the American Chemical Society, Год журнала: 2024, Номер 146(36), С. 25321 - 25327
Опубликована: Сен. 2, 2024
Cyclohexene cannot be polymerized via ring-opening polymerization under any conditions due to its lack of ring strain. A hypothetical polycyclohexene would therefore have a strong thermodynamic driving force depolymerize monomer if metathesis catalyst were provided while otherwise having thermal and hydrolytic stability normal because hydrocarbon backbone. We envisioned access this unattainable family polymers the alternating diene an alkene. Ethyl aluminum chloride was found promote highly butadiene methacrylate when radically initiated at room temperature, resulting in formal structures. Ultrahigh molecular weight (up 1750 kDa) can synthesized decagram scale high conversions. The presumably atactic copolymers exhibited semicrystallinity, leading toughness. In presence small amount Grubbs catalyst, generated fully depolymerized ambient temperatures into pure constituent cyclohexene. strategy using orthogonal chemistry for depolymerization processes allows polymer structures with subambient ceiling without ultralow temperature synthesis or relying on monomer-polymer equilibrium.
Язык: Английский
Процитировано
7
Nature Communications, Год журнала: 2024, Номер 15(1)
Опубликована: Окт. 1, 2024
Язык: Английский
Процитировано
7
Organic & Biomolecular Chemistry, Год журнала: 2025, Номер unknown
Опубликована: Янв. 1, 2025
Selenium-based catalysts have recently been utilized to facilitate a variety of new organic transformations, owing their intrinsic advantages, including low cost, toxicity, stability in both air and water, strong compatibility with diverse functional groups. The difunctionalization alkenes-the process incorporating two groups onto carbon-carbon double bond-has garnered particular interest within the chemical community its significant applications synthesis. Recently, organoselenium-catalyzed alkenes has emerged as an ideal powerful route obtain high-value vicinal difunctionalized molecules. This review emphasizes recent advancements this rapidly evolving field, focusing on scope, limitations, mechanisms various reactions.
Язык: Английский
Процитировано
1
ACS Macro Letters, Год журнала: 2025, Номер unknown, С. 377 - 384
Опубликована: Март 8, 2025
The effective management of plastic waste is critical for environmental sustainability. This work explores the use carbocation catalysts recycling common polyesters and polycarbonates through alcoholysis. We demonstrate complete depolymerization end-of-life materials investigate relationship between catalytic reactivity structural features compounds, including cations their counteranions. Carbocations function as Lewis acids, facilitating interaction with carbonyls in polymer chains. Moreover, our approach enables hierarchical degradation polyester blends. research not only elucidates role carbocations alcoholysis these polymers, but also establishes a metal-free process efficient plastics.
Язык: Английский
Процитировано
1
Nature Sustainability, Год журнала: 2025, Номер unknown
Опубликована: Март 11, 2025
Язык: Английский
Процитировано
1
Reviews in Environmental Science and Bio/Technology, Год журнала: 2025, Номер unknown
Опубликована: Апрель 24, 2025
Язык: Английский
Процитировано
1
Опубликована: Янв. 1, 2025
Язык: Английский
Процитировано
0