Strong and Tough Supramolecular Covalent Adaptable Networks with Room‐Temperature Closed‐Loop Recyclability

Advanced Materials, Год журнала: 2022, Номер 35(7)

Опубликована: Ноя. 11, 2022

Development of closed-loop chemically recyclable plastics (CCRPs) that can be widely used in daily life a fundamental solution to the global plastic waste crisis. Hence, it is great significance develop easy-to-recycle CCRPs possess superior or comparable material properties commodity plastics. Here, novel dual crosslinked CCRP, namely, supramolecular covalent adaptable networks (supra-CANs), reported, which not only displays mechanical higher than strong and tough polycarbonate, but also exhibits excellent solvent resistance as thermosets. The supra-CANs are constructed by introducing reversible noncovalent crosslinks into dynamic polymer networks, resulting highly stiff thermosets exhibit thermoplastic-like ductile behaviors well reprocessability rehealability. In contrast, analogs do have (CANs) show elastomeric with significantly decreased strength. Importantly, developed CANs converted back initial monomers high yields purity at room temperature, even additives, enables sustainable polymer-monomer-polymer circulation. This work provides new design principles for high-performance polymers substitutes conventional

Язык: Английский

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Recyclable and (Bio)degradable Polyesters in a Circular Plastics Economy

Chemical Reviews, Год журнала: 2024, Номер 124(7), С. 4393 - 4478

Опубликована: Март 22, 2024

Polyesters carrying polar main-chain ester linkages exhibit distinct material properties for diverse applications and thus play an important role in today's plastics economy. It is anticipated that they will even greater tomorrow's circular economy focuses on sustainability, thanks to the abundant availability of their biosourced building blocks presence bonds can be chemically or biologically cleaved demand by multiple methods bring about more desired end-of-life plastic waste management options. Because this potential promise, there have been intense research activities directed at addressing recycling, upcycling biodegradation existing legacy polyesters, designing biorenewable alternatives, redesigning future polyesters with intrinsic chemical recyclability tailored performance rival commodity are either petroleum based and/or hard recycle. This review captures these exciting recent developments outlines challenges opportunities. Case studies poly(lactic acid), poly(3-hydroxyalkanoate)s, poly(ethylene terephthalate), poly(butylene succinate), poly(butylene-adipate presented, emerging recyclable comprehensively reviewed.

Язык: Английский

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Tough while Recyclable Plastics Enabled by Monothiodilactone Monomers

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(3), С. 1877 - 1885

Опубликована: Янв. 3, 2023

The current scale of plastics production and the attendant waste disposal issues represent an underexplored opportunity for chemically recyclable polymers. Typical polymers are subject to trade-off between monomer's polymerizability polymer's depolymerizability as well insufficient performance practical applications. Herein, we demonstrate that a single atom oxygen-by-sulfur substitution relatively highly strained dilactone is effective robust strategy converting "non-recyclable" polyester into polymer by lowering ring strain energy in monomer (from 16.0 kcal mol-1 9.1 monothiodilactone). These monothio-modification monomers enable both high/selective recyclability, otherwise conflicting features typical monomer, evidenced regioselective ring-opening, minimal transthioesterifications, quantitative recovery pristine monomer. Computational experimental studies n→π* interaction adjacent ester thioester backbone has been implicated high selectivity propagation over transthioesterification. resulting demonstrates with its mechanical properties being comparable some commodity polyolefins. Thio-modification powerful enabling conversion six-membered dilactones tough thermoplastics exhibit promise next-generation sustainable

Язык: Английский

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Redesigned Hybrid Nylons with Optical Clarity and Chemical Recyclability

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(12), С. 5366 - 5376

Опубликована: Март 15, 2022

Aliphatic polyamides, or nylons, are typically highly crystalline and thermally robust polymers used in high-performance applications. Nylon 6, a high-ceiling-temperature (HCT) polyamide from ε-caprolactam, lacks expedient chemical recyclability, while low-ceiling temperature (LCT) nylon 4 pyrrolidone exhibits complete but it is unstable not melt-processable. Here, we introduce hybrid nylon, 4/6, based on bicyclic lactam composed of both HCT ε-caprolactam LCT motifs hybridized offspring structure. Hybrid 4/6 overcomes trade-offs (de)polymerizability performance properties the parent exhibiting excellent polymerization facile depolymerization characteristics. This stereoregular forms nanocrystalline domains, allowing optical clarity high thermal stability, however, without displaying melting transition before decomposition. Of series statistical copolymers comprising 4, 50/50 copolymer achieves greatest synergy reactivity polymer each homopolymer, offering an amorphous with favorable properties, including clarity, glass temperature, melt processability, full recyclability.

Язык: Английский

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Depolymerization within a Circular Plastics System

Chemical Reviews, Год журнала: 2024, Номер 124(5), С. 2617 - 2650

Опубликована: Фев. 22, 2024

The societal importance of plastics contrasts with the carelessness which they are disposed. Their superlative properties lead to economic and environmental efficiency, but linearity puts climate, human health, global ecosystems at risk. Recycling is fundamental transitioning this linear model into a more sustainable, circular economy. Among recycling technologies, chemical depolymerization offers route virgin quality recycled plastics, especially when valorizing complex waste streams poorly served by mechanical methods. However, exists in interlinked system end-of-life fates, complementarity each approach key environmental, economic, sustainability. This review explores recent progress made five commercial polymers: poly(ethylene terephthalate), polycarbonates, polyamides, aliphatic polyesters, polyurethanes. Attention paid not only catalytic technologies used enhance efficiencies also interrelationship other systemic constraints imposed Novel polymers, designed for depolymerization, concisely reviewed terms their underlying chemistry potential integration current plastic systems.

Язык: Английский

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Sustainable developments in polyolefin chemistry: Progress, challenges, and outlook

Progress in Polymer Science, Год журнала: 2023, Номер 143, С. 101713 - 101713

Опубликована: Июнь 25, 2023

Язык: Английский

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Ring-Opening Polymerization for the Goal of Chemically Recyclable Polymers

Macromolecules, Год журнала: 2023, Номер 56(3), С. 731 - 750

Опубликована: Фев. 6, 2023

A crucial modern dilemma relates to the ecological crisis created by excess plastic waste production. An emerging technology for reducing is production of "chemically recyclable" polymers. These polymers can be efficiently synthesized through ring-opening polymerization (ROP/ROMP) and later recycled pristine monomer ring-closing depolymerization, in an efficient circular-type system. This Perspective aims explore chemistry involved preparation these monomer/polymer systems, while also providing overview challenges involved, including future directions.

Язык: Английский

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Chemical Recycling of Commercial Poly(l-lactic acid) to l-Lactide Using a High-Performance Sn(II)/Alcohol Catalyst System

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(36), С. 19840 - 19848

Опубликована: Сен. 1, 2023

Poly(l-lactic acid) (PLLA) is a leading commercial polymer produced from biomass, showing useful properties for plastics and fiber applications; after use, it compostable. One area improvement postconsumer waste PLLA chemical recycling to monomer (CRM), i.e., the formation of l-lactide (l-LA) plastic. This process currently feasible at high reaction temperatures shows low catalytic activity accompanied, in some cases, by side reactions, including epimerization. Here, Sn(II) catalyst, applied with nonvolatile alcohol, enables highly efficient CRM yield l-LA excellent purity (92% yield, >99% theoretical max.). The depolymerization performed using neat films (160 °C) under nitrogen flow or vacuum. operates outstanding activity, achieving turnover frequencies which are up 3000× higher than previously catalysts loadings 6000× lower catalysts. catalyst system achieves TOF = 3000 h–1 0.01 mol % 1:10,000 catalyst:PLLA loading. plastic packaging (coffee cup lids) produces pure selectivity. new (Sn + alcohol) can itself be recycled four times different "batch degradations" maintains its productivity,

Язык: Английский

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Ring-Opening Polymerization of Lactones to Prepare Closed-Loop Recyclable Polyesters

Macromolecules, Год журнала: 2024, Номер 57(5), С. 1919 - 1940

Опубликована: Фев. 22, 2024

The large production and indiscriminate disposal of plastics have resulted in serious resource global environmental crises, which has raised a demand to develop more sustainable circular economy. An ideal strategy address the end-of-life issue is next-generation polymers with closed-loop life cycles, can be selectively depolymerized back monomers at end their service life. Aliphatic polyesters prepared by ring-opening polymerization (ROP) moderately strained lactones shown great potential recyclable polymers. This Perspective highlights recent achievements for that are derived from four-, five-, six-, seven-membered focusing on discussion thermodynamic kinetic considerations, monomer design principles polymer preparations, material properties, chemical recyclability. Finally, current challenges possible directions also discussed.

Язык: Английский

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Deconstruction of Polymers through Olefin Metathesis

Chemical Reviews, Год журнала: 2024, Номер 124(11), С. 7007 - 7044

Опубликована: Май 24, 2024

The consumption of synthetic polymers has ballooned; so the amount post-consumer waste generated. current polymer economy, however, is largely linear with most being either landfilled or incinerated. lack recycling, together sizable carbon footprint industry, led to major negative environmental impacts. Over past few years, chemical recycling technologies have gained significant traction as a possible technological route tackle these challenges. In this regard, olefin metathesis, its versatility and ease operation, emerged an attractive tool. Here, we discuss developments in olefin-metathesis-based technologies, including development new materials application metathesis commercial materials. We delve into structure–reactivity relationships context polymerization–depolymerization behavior, how experimental conditions influence deconstruction outcomes, reaction pathways underlying approaches. also look at hurdles adopting relevant future directions for field.

Язык: Английский

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