New Advances in Covalent Network Polymers via Dynamic Covalent Chemistry

Chemical Reviews, Journal Year: 2024, Volume and Issue: 124(12), P. 7829 - 7906

Published: June 3, 2024

Covalent network polymers, as materials composed of atoms interconnected by covalent bonds in a continuous network, are known for their thermal and chemical stability. Over the past two decades, these have undergone significant transformations, gaining properties such malleability, environmental responsiveness, recyclability, crystallinity, customizable porosity, enabled development integration dynamic chemistry (DCvC). In this review, we explore innovative realm polymers focusing on recent advances achieved through application DCvC. We start examining history fundamental principles DCvC, detailing its inception core concepts noting key role reversible bond formation. Then reprocessability DCvC is thoroughly discussed, starting from milestones that marked evolution progressing to current trends applications. The influence crystallinity then reviewed, covering diversity, synthesis techniques, functionalities. concluding section, address challenges faced field speculates potential future directions.

Language: Английский

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A tutorial review of linear rheology for polymer chemists: basics and best practices for covalent adaptable networks

Polymer Chemistry, Journal Year: 2024, Volume and Issue: 15(9), P. 815 - 846

Published: Jan. 1, 2024

This tutorial review of linear viscoelasticity is targeted at polymer chemists working with covalent adaptable networks. It provides an overview concepts, analysis, misconceptions, and best practices for rheological experiments.

Language: Английский

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Accessing pluripotent materials through tempering of dynamic covalent polymer networks

Science, Journal Year: 2024, Volume and Issue: 383(6682), P. 545 - 551

Published: Feb. 1, 2024

Pluripotency, which is defined as a system not fixed to its developmental potentialities, typically associated with biology and stem cells. Inspired by this concept, we report synthetic polymers that act single "pluripotent" feedstock can be differentiated into range of materials exhibit different mechanical properties, from hard brittle soft extensible. To achieve this, have exploited dynamic covalent networks contain labile, thia-Michael bonds, whose extent bonding thermally modulated retained through tempering, akin the process used in metallurgy. In addition, show shape memory behavior these tailored tempering patterned spatially control properties.

Language: Английский

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Liquid Crystal Elastomers for Actuation: A Perspective on Structure-Property-Function Relation

Progress in Polymer Science, Journal Year: 2024, Volume and Issue: 153, P. 101829 - 101829

Published: May 10, 2024

Liquid crystal elastomers (LCEs) have long held significant promise as materials for artificial muscles and smart actuators. Recent advancements in this field introduced innovative LCE structures at various scales, resulting novel properties functionalities that further accentuate their actuation advantages, bolstering potential future soft systems. The ongoing pursuit of enhanced performance functionality actuators, essential advancing them towards superior material-based machines devices, is intricately linked to the understanding fundamental structure-property-function relationships. This review provides a perspective on these relationships across multiple structural levels, encompassing chemical structures, mesophase micro-to-macroscale programmed structures. It delves into impact key actuation-related properties, features, functionalities. aspires provide valuable insights design high-performance development exceptional modes behaviors, expansion achievable functionality.

Language: Английский

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Taking dynamic covalent chemistry out of the lab and into reprocessable industrial thermosets

Nature Reviews Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 31, 2025

Language: Английский

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Remolding and Deconstruction of Industrial Thermosets via Carboxylic Acid-Catalyzed Bifunctional Silyl Ether Exchange

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(3), P. 1916 - 1923

Published: Jan. 13, 2023

Convenient strategies for the deconstruction and reprocessing of thermosets could improve circularity these materials, but most approaches developed to date do not involve established, high-performance engineering materials. Here, we show that bifunctional silyl ether, i.e., R'O-SiR2-OR'', (BSE)-based comonomers generate covalent adaptable network analogues industrial thermoset polydicyclopentadiene (pDCPD) through a novel BSE exchange process facilitated by low-cost food-safe catalyst octanoic acid. Experimental studies density functional theory calculations suggest an mechanism involving ester intermediates with formation rates strongly depend on Si-R2 substituents. As result, pDCPD manufactured display temperature- time-dependent stress relaxation as function their Moreover, bulk remolding is enabled first time. Altogether, this work presents new approach toward installation exchangeable bonds into commercial establishes acid-catalyzed versatile addition toolbox dynamic chemistry.

Language: Английский

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C–H Functionalization of Polyolefins to Access Reprocessable Polyolefin Thermosets

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(50), P. 27450 - 27458

Published: Dec. 11, 2023

Upcycling plastic waste into reprocessable materials with performance-advantaged properties would contribute to the development of a circular plastics economy. Here, we modify branched polyolefins and postconsumer polyethylene through versatile C–H functionalization approach using thiosulfonates as privileged radical group transfer functionality. Cross-linking functionalized polytopic amines provided dynamically cross-linked polyolefin networks enabled by associative bond exchange diketoenamine A combination resonant soft X-ray scattering grazing incidence revealed hierarchical phase morphology in which diketoenamine-rich microdomains phase-separate within amorphous regions between crystallites. The dynamic covalent cross-links microphase separation results useful improved mechanical properties, including ∼4.5-fold increase toughness, reduction creep deformation at temperatures relevant use, high-temperature structural stability compared parent polyolefin. nature provides stress relaxation elevated temperatures, iterative reprocessing polymer network little cycle-to-cycle property fade. ability convert thermoformable material attractive thermomechanical additional optionality for upcycling enable future circularity.

Language: Английский

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Structure, Dynamics, and Rheology of Vitrimers

Macromolecules, Journal Year: 2023, Volume and Issue: 56(19), P. 8080 - 8093

Published: Sept. 29, 2023

Vitrimers are associative covalent adaptable networks that undergo reversible bond-exchange reactions while maintaining a fixed cross-linking density with changing temperature. To date, experimental studies rely on macroscopic rheology have not been able to reveal topological changes and microscopic dynamics in these materials. Here, coarse-grained molecular simulations combined Monte Carlo method implemented investigate the structural changes, dynamics, linear of unentangled side-chain-linked vitrimers conjunction sticky Rouse model (SRM). We find there is minor variation structure The dynamic heterogeneities behavior system increase remarkably when approaching freezing transition temperature Tv. Quantitative agreement between simulation results SRM predictions observed for stress relaxation, elastic loss moduli, relative mean-squared displacement, especially at intermediate- long-time or low-frequency regimes, where time–temperature superposition principle satisfied. obtain scaling collapse curve bond relaxation time, zero-shear viscosity, horizontal shift factors without introducing any parameters, suggesting exhibit similar even presence loop defects. Moreover, good those predicted by SRM, indicating fast rate can be analyzed via single-chain approach based SRM.

Language: Английский

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Phase separation in supramolecular and covalent adaptable networks

Soft Matter, Journal Year: 2023, Volume and Issue: 19(16), P. 2857 - 2877

Published: Jan. 1, 2023

In this review we highlight the underlying mechanisms of phase separation in dynamic polymer networks, distinguishing between supramolecular networks and covalent adaptable discuss effect on material properties.

Language: Английский

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Enhancing the Equilibrium of Dynamic Thia-Michael Reactions through Heterocyclic Design

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(26), P. 14427 - 14434

Published: June 23, 2023

Although the catalyst-free dynamic thia-Michael (tM) reaction has been leveraged for a range of significant applications in materials science and pharmaceutical development, exploiting its full potential limited by relatively low equilibrium constants. To address this shortcoming, new series catalyst-free, room-temperature acceptors bearing an isoxazolone motif were developed utilized to access both covalent networks linear polymers. By leveraging generation aromaticity upon thiol addition tuning electronic-withdrawing/donating nature acceptor at two different sites, wide constants (Keq ∼1000 ∼100,000 M-1) obtained, constituting 2 orders magnitude increase compared their noncyclic benzalcyanoacetate analogues. Integration into ditopic isoxazolone-based Michael allowed bulk polymers; these not only exhibited tailorable thermomechanical properties based on composition, but higher Keq tM bonds resulted more mechanically robust relative past designs. Furthermore, solution-state formation polymers was achieved thanks increased acceptors.

Language: Английский

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