Mechanically Robust, Recyclable, and Self‐Healing Polyimine Networks

Advanced Science, Год журнала: 2023, Номер 10(19)

Опубликована: Апрель 23, 2023

To achieve energy saving and emission reduction goals, recyclable healable thermoset materials are highly attractive. Polymer copolymerization has been proven to be a critical strategy for preparing high-performance polymeric materials. However, it remains huge challenge develop Here, polyimine dynamic networks based on two monomers with bulky pendant groups, which not only displayed mechanical properties higher than the strong tough polymers, e.g., polycarbonate, but also excellent self-repairing capability recyclability as thermosets developed. Owing stability of conjugation effect by aromatic benzene rings, final far more stable reported counterparts, exhibiting hydrolysis resistance under both alkaline condition most organic solvents. These structure can completely depolymerized into recovery in an acidic aqueous solution at ambient temperature. Resulting from units, this method allows exchange reactions vitrimer easily within minutes self-healing function. Moreover, introduction trifluoromethyl diphenoxybenzene backbones significantly increases tensile This work provides effective fabricating polymer multiple functions.

Язык: Английский

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Deciphering the Self-Catalytic Mechanisms of Polymerization and Transesterification in Polybenzoxazine Vitrimers

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(19), С. 13367 - 13376

Опубликована: Май 2, 2024

The use of internal catalysts has emerged as a pivotal design principle to facilitate dynamic exchanges within covalent adaptable networks (CANs). Polybenzoxazines, specifically, have shown considerable potential in generating vitrimers through thermally induced transesterification reactions catalyzed internally by tertiary amines. This study aims investigate the chemical complexities benzoxazine vitrimers. To achieve this, model molecules using various phenolic acids and amino-alcohol derivatives were synthesized precursors. structure these was fully elucidated nuclear magnetic resonance (NMR). Differential scanning calorimetry (DSC) rheology experiments evidenced accelerated network formation precursors due presence aliphatic −OH groups. Thermogravimetric analysis coupled with microcomputed gas chromatography (TGA-μGC) used provide evidence reactions. results showed that spatial proximity between amine hydroxyl groups significantly enhances rate exchange, attributed neighboring group participation (NGP) effect. Interestingly, kinetic complementary NMR techniques revealed thermal latency toward its opening is needed trigger exchange. highlights crucial role steric hindrance basicity promoting exchange an system.

Язык: Английский

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Sustainable polyester vitrimer capable of fast self-healing and multiple shape-programming via efficient synthesis and configuration processing

Journal of Materials Chemistry A, Год журнала: 2023, Номер 11(20), С. 10912 - 10926

Опубликована: Янв. 1, 2023

Considering that environmental friendliness and energy conservation are becoming crucial, it is urgent to advance the sustainability of materials in terms their lifecycle, including synthesis, processing, application.

Язык: Английский

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Aza-Michael Chemistry for PDMS-Based Covalent Adaptable Elastomers: Design and Dual Role of the Silica Filler

Macromolecules, Год журнала: 2024, Номер 57(10), С. 4817 - 4825

Опубликована: Май 7, 2024

In this study, polydimethylsiloxane (PDMS)-based covalent adaptable networks have been prepared in a one-pot, catalyst-free way which dynamic β-amino esters (BAEs) are introduced via aza-Michael addition between available acrylate/amine-terminated PDMS-compounds. The straightforward introduction of those BAE-groups such high-value elastomers provides the ability to relax applied stress at elevated temperatures and hence capability reshaping by compression molding least 5 times without significant changes properties. Moreover, mechanical properties tunable varying cross-linker and/or filler content. Interestingly, utilization silica fillers not only enhances network formation but also accelerates exchange reactions, resulting twice faster relaxation while maintaining creep resistance service temperatures.

Язык: Английский

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Thia-Michael Reaction: The Route to Promising Covalent Adaptable Networks

Polymers, Год журнала: 2022, Номер 14(20), С. 4457 - 4457

Опубликована: Окт. 21, 2022

While the Michael addition has been employed for more than 130 years synthesis of a vast diversity compounds, reversibility this reaction when heteronucleophiles are involved generally less considered. First applied to medicinal chemistry, reversible character hetero-Michael reactions recently explored Covalent Adaptable Networks (CANs), in particular thia-Michael and aza-Michael reaction. In these cross-linked networks, exchange take place between two adducts by successive dissociation association steps. order understand precisely control CANs, it is necessary get an insight into critical parameters influencing rates reconsidering previous studies on matters. This review presents progress understanding over as well latest developments plausible future directions prepare CANs based The potential application highlighted specific section with comparison thia-Michael-based CANs.

Язык: Английский

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Biobased and aromatic Covalent Adaptable Networks: When architectures meet properties, within the framework of a circular bioeconomy

Materials Science and Engineering R Reports, Год журнала: 2024, Номер 161, С. 100882 - 100882

Опубликована: Ноя. 9, 2024

Язык: Английский

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Dynamic PEG–PLA/Hydroxyurethane Networks Based on Imine Bonds as Reprocessable Elastomeric Biomaterials

Biomacromolecules, Год журнала: 2023, Номер 24(8), С. 3472 - 3483

Опубликована: Июль 17, 2023

The development of dynamic covalent chemistry opens the way to design materials able be reprocessed by an internal exchange reaction under thermal stimulus. Imine differs from other reactions its relatively low temperature activation. In this study, amine-functionalized star-shaped PEG–PLA and aldehyde-functionalized hydroxyurethane modifier were combined produce PEG–PLA/hydroxyurethane networks incorporating imine bonds. mechanical properties these new evaluated as a function initial ratio amine/aldehyde used during synthesis. Rheological analyses highlighted behavior vitrimers at moderate (60–85 °C) provided flow activation energies. Additionally, reprocessability was assessed comparing material before reshaping after three reprocessing cycles (1 ton, 1 h, 70 °C). Hence, can easily designed satisfy specific medical application without loss. This work generation combining degradable copolymers modifiers, which could find applications in shape devices on-demand mild conditions.

Язык: Английский

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β-Amino amide based covalent adaptable networks with high dimensional stability

Polymer Chemistry, Год журнала: 2023, Номер 15(1), С. 11 - 16

Опубликована: Дек. 6, 2023

Catalyst-free reversible β-amino amides in covalent adaptable networks with reprocessability and high dimensional stability.

Язык: Английский

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Internal hydrogen bonding of imines to control and enhance the dynamic mechanical properties of covalent adaptable networks

European Polymer Journal, Год журнала: 2023, Номер 195, С. 112209 - 112209

Опубликована: Июнь 10, 2023

Covalent Adaptable Networks (CANs) have the potential to replace current thermoset materials, as dynamic covalent bonds in CANs enable reprocessability and recycling of crosslinked polymer networks. A limitation is, however, that they are generally susceptible towards creep, bond exchange reactions facilitate stress relaxation. In this work, we propose use internal hydrogen bonding polyimine an efficient tool enhance creep resistance (at operating temperature) further control mechanical properties, while still enabling malleability at elevated temperatures. We able show on a small-molecule level ortho-substituted hydroxy groups aromatic imines stabilise imine result is formed between group. Furthermore, with incorporated ortho significantly enhanced material can be seen glass transition temperature (Tg), elastic modulus (G'), solvent resistance. While also consider additional steric electronic effects might arisen due installation groups, find stabilising effect primarily dictating performance.

Язык: Английский

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How to Characterize Covalent Adaptable Networks: A User Guide

ACS Polymers Au, Год журнала: 2025, Номер unknown

Опубликована: Апрель 17, 2025

Язык: Английский

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