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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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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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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Recent advances in oxidative degradation of plastics

Chemical Society Reviews, Год журнала: 2024, Номер 53(14), С. 7309 - 7327

Опубликована: Янв. 1, 2024

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 of polymers under mild conditions. This tutorial review presents overview degradation, from its earliest examples emerging strategies. briefly discusses the motivation development with focus on underlying mechanisms. Then, we will examine modern studies primarily relevant catalytic degradation. Lastly, highlight some unique using unconventional approaches for polymer such electrochemistry.

Язык: Английский

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Visible light–triggered depolymerization of commercial polymethacrylates

Science, Год журнала: 2025, Номер 387(6736), С. 874 - 880

Опубликована: Фев. 20, 2025

The reversion of vinyl polymers with carbon-carbon backbones to their monomers represents an ideal path alleviate the growing plastic waste stream. However, depolymerizing such stable materials remains a challenge, state-of-the-art methods relying on "designer" that are neither commercially produced nor suitable for real-world applications. In this work, we report main chain-initiated, visible light-triggered depolymerization directly applicable commercial containing undisclosed impurities (e.g., comonomers, additives, or dyes). By in situ generation chlorine radicals from solvent, near-quantitative (>98%) polymethacrylates could be achieved regardless synthetic route radical ionic polymerization), end group, and molecular weight (up 1.6 million daltons). possibility perform multigram-scale depolymerizations confer temporal control renders methodology versatile general recycling.

Язык: Английский

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Thermally Stable and Chemically Recyclable Poly(ketal-ester)s Regulated by Floor Temperature

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(22), С. 15428 - 15437

Опубликована: Май 25, 2024

Chemical recycling to monomers (CRM) offers a promising closed-loop approach transition from current linear plastic economy toward more sustainable circular paradigm. Typically, this 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) decomposition ∼200 °C. In contrast, floor (Tf)-regulated polymers, particularly those synthesized via ring-opening polymerization (ROP) macrolactones, inherently exhibit enhanced thermodynamic stability increases. However, development Tf regulated chemically recyclable remains relatively underexplored. context, judicious design and efficient synthesis biobased macrocyclic diester monomer (HOD), we developed type -regulated poly(ketal-ester) (PHOD). First, entropy-driven ROP HOD generated high-molar mass PHOD exceptional Td,5% reaching up 353 Notably, it maintains high 345 °C even without removing catalyst. This contrasts markedly PGBL, which spontaneously depolymerizes back above its in presence Second, displays outstanding chemical recyclability at room within just 1 min tBuOK. Finally, copolymerization pentadecanolide (PDL) high-performance copolymers (PHOD-co-PPDL) tunable mechanical properties both components.

Язык: Английский

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Enabling Closed‐Loop Circularity of “Non‐Polymerizable” α, β‐Conjugated Lactone Towards High‐Performance Polyester with the Assistance of Cyclopentadiene

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(22)

Опубликована: Март 16, 2024

Abstract Chemical recycling of polymers to monomers presents a promising solution the escalating crisis associated with plastic waste. Despite considerable progress made in this field, primary efforts have been focused on redesigning new produce readily recyclable polymers. In contrast, limited research into potential seemingly “non‐polymerizable” has conducted. Herein, we propose paradigm that leverages “chaperone”‐assisted strategy establish closed‐loop circularity for α, β‐conjugated lactone, 5,6‐dihydro‐2H‐pyran‐2‐one (DPO). The resulting PDPO, structural analogue poly(δ‐valerolactone) (PVL), exhibits enhanced thermal properties melting point ( T m ) 114 °C and decomposition temperature d,5% 305 °C. Notably, owing similarity between DPO δ‐VL, copolymerization generates semi‐crystalline P(DPO‐ co ‐VL)s irrespective incorporation ratio. Intriguingly, inherent C=C bonds enable their convenient post‐functionalization via Michael‐addition reaction. Lastly, PDPO was demonstrated be chemically ring‐closing metathesis (RCM), representing significant step towards pursuit enabling lactones without altering ultimate polymer structure.

Язык: Английский

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Torsional Strain Enabled Ring‐Opening Polymerization towards Axially Chiral Semiaromatic Polyesters with Chemical Recyclability

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(13)

Опубликована: Фев. 15, 2024

Abstract The development of new chemically recyclable polymers via monomer design would provide a transformative strategy to address the energy crisis and plastic pollution problem. Biaryl‐fused cyclic esters were targeted generate axially chiral polymers, which impart material performance. To overcome non‐polymerizability biaryl‐fused DBO, ester Me‐DBO installed with dimethyl substitution was prepared enable its polymerizability enhancing torsional strain. Impressively, readily went through well‐controlled ring‐opening polymerization, producing polymer P(Me‐DBO) high glass transition temperature ( T g >100 °C). Intriguingly, mixing these complementary enantiopure containing axial chirality promoted transformation from amorphous crystalline material, affording semicrystalline stereocomplex melting more than 300 °C. capable depolymerizing back in efficiency, highlighting an excellent recyclability.

Язык: Английский

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Closed-loop recyclable polymers: from monomer and polymer design to the polymerization–depolymerization cycle

Chemical Society Reviews, Год журнала: 2024, Номер 53(19), С. 9609 - 9651

Опубликована: Янв. 1, 2024

We present the state-of-the-art of circular polymers based on monomer and polymer design reversible ring-opening addition polymerization reactions without involvement other reactants.

Язык: Английский

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Toughening Poly(lactic acid) without Compromise – Statistical Copolymerization with a Bioderived Bicyclic Lactone

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Янв. 28, 2025

Poly(lactic acid) (PLA) offers a renewable and degradable alternative to petroleum-based plastic, but its mechanical properties are not ideal for many applications. Herein, we describe the synthesis polymerization of 2-oxo-3,8-dioxabicyclo[3.2.1]octane (ODO), bioderived bicyclic lactone, show that copolymers l-lactide (LA) with small amounts ODO have improved over PLA. Homopolymerization poly(oxo-3,8-dioxabicyclo[3.2.1]octane) (PODO) is optimized both solution-phase, organocatalytic melt-phase, metal-catalyzed conditions. In comparison monocyclic analog, ε-caprolactone (CL), has lower enthalpy faster rate polymerization. PODO an amorphous, elastomeric polyester Tg 90 °C higher than poly(ε-caprolactone) (PCL). Statistical copolymerization LA fractions yields tough transparent thermoplastics 12× elongation at break compared native PLA, while maintaining Tg, Young's modulus (E), yield strength. Together, these results how incorporation tetrahydrofuran ring alters lactone polymerizability thermomechanical homopolymer copolymer materials.

Язык: Английский

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