Ultrafast Thermal RAFT Depolymerization at Higher Solid Contents

ACS Macro Letters, Journal Year: 2025, Volume and Issue: unknown, P. 235 - 240

Published: Feb. 10, 2025

Although thermal solution RAFT depolymerization has recently emerged as an efficient chemical recycling methodology, current approaches require specialized solvents (i.e., dioxane), typically suffer from extended reaction times, and operate exclusively under highly dilute conditions 5 mM repeat unit concentration). To circumvent these limitations, a commercial radical initiator is introduced to kinetically untrap the promote chain-end activation. By varying concentration, remarkable rate acceleration (up 72 times faster) can be observed, enabling completion of within min. Notably, 20-fold increase in concentration did not appreciably compromise final yield, while very high percentages monomer could recovered wide range solvents, including dimethyl sulfoxide, anisole, xylene, acetonitrile, toluene, trichlorobenzene. Our findings only offer intriguing mechanistic aspects, but also significantly expand scope applications depolymerization.

Language: Английский

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Ten Problems in Polymer Reactivity Prediction

Macromolecules, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 17, 2025

Language: Английский

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Depolymerizing off-the-shelf polymethacrylates with visible light

Chem, Journal Year: 2025, Volume and Issue: unknown, P. 102540 - 102540

Published: March 1, 2025

Language: Английский

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Functional Group Transformation Approach to Chemically Recyclable Polymers from Ultra-Low to Moderate Strain Monomers

Macromolecules, Journal Year: 2025, Volume and Issue: 58(8), P. 3898 - 3905

Published: April 11, 2025

Ring-opening metathesis polymerization (ROMP) has been widely used for the synthesis of functional polymers. However, most ROMP-derived polymers are nondepolymerizable, limiting their sustainability and eco-friendiness. While recent advances in designing low-strain cyclic olefin monomers have enabled ROMP depolymerizable polyolefins, scope these remains limited due to narrow range ring strain energies (RSEs = 4.7-5.4 kcal/mol) required allow both depolymerization a closed-loop recycling process. Herein, we present new class chemically recyclable polyolefins based on cycloheptene derivatives with RSEs ranging from 3.8 7.2 kcal/mol. The wide establishment structure-polymerizability-depolymerizability relationship, shedding light role RSE depolymerization. A group transformation (FGT) strategy, harnessing reversible ketone-to-acetal chemistry, was developed overcome low polymerizability moderate depolymerizability made moderate-strain monomers. This FGT approach not only enhanced chemical moderately but also provided access highly that challenging synthesize through direct ultralow Moreover, thermal properties this study tunable, broad glass transition temperatures (-7 104 °C), highlighting potential various applications.

Language: Английский

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Improving the Accuracy of Ceiling Temperature Measurements: Best Practices and Common Pitfalls

Macromolecules, Journal Year: 2025, Volume and Issue: unknown

Published: April 13, 2025

Language: Английский

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β-Pinene-Based Polyester from Renewable Feedstock with Elastomeric Behavior

Macromolecules, Journal Year: 2025, Volume and Issue: unknown

Published: April 17, 2025

Language: Английский

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Unraveling the Mechanism of Catalyzed Melt-Phase Polyester Depolymerization via Studies of Kinetics and Model Reactions

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(37), P. 25745 - 25754

Published: Sept. 3, 2024

Developing a mechanistic understanding of catalyzed melt-phase depolymerization processes is utmost importance to the rapidly expanding field circular polymers with closed chemical loop. Herein, we present methodology probe mechanism metal-catalyzed polyesters utilizing an approach centered on studies kinetics by thermogravimetric analysis and model reactions. Kinetic parameters associated prototypical Lewis-acid-catalyzed representative polyesters, including poly(δ-valerolactone) (PVL), poly(lactic acid), poly(γ-butyrolactone), are elucidated. Focusing PVL for further investigation mechanism, effects its molar mass, topology, end-group chemistry examined in detail. Overall, ring-closing process monomer from polyester hydroxyl-chain ends proposed as key step, although has relatively large zip length (≈ 320) follows nonimmortal kinetics.

Language: Английский

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Bulk depolymerization of PMMA using difunctional pyromellitic or monofunctional phthalimidic ATRP initiators

European Polymer Journal, Journal Year: 2024, Volume and Issue: unknown, P. 113646 - 113646

Published: Dec. 1, 2024

Language: Английский

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Closed-Loop Chemical Recycling of a Biobased Poly(oxanorbornene-fused γ-butyrolactone)

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 2, 2024

New polymers, properly designed for end-of-life and efficiently formed from renewable carbon, are key to the transition a more sustainable circular plastics economy. Ring-opening polymerization (ROP) of bicyclic lactones is promising method production intrinsically recyclable polyesters, but most lactone monomers lack an efficient synthesis route biobased starting materials, even though this essential sustainably account material loss during life cycle. Herein, we present exceptionally rapid controlled fully tricyclic oxanorbornene-fused γ-butyrolactone monomer (

Language: Английский

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