Aza-Michael Chemistry for PDMS-Based Covalent Adaptable Elastomers: Design and Dual Role of the Silica Filler DOI
Loc Tan Nguyen, Chiel Mertens, Filip Du Prez

et al.

Macromolecules, Journal Year: 2024, Volume and Issue: 57(10), P. 4817 - 4825

Published: May 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.

Language: Английский

Fast Dynamic Siloxane Exchange Mechanism for Reshapable Vitrimer Composites DOI
Tapas Debsharma, Virginia Amfilochiou, Aleksandra A. Wróblewska

et al.

Journal of the American Chemical Society, Journal Year: 2022, Volume and Issue: 144(27), P. 12280 - 12289

Published: June 27, 2022

To develop siloxane-containing vitrimers with fast dynamic characteristics, different mechanistic pathways have been investigated using a range of catalysts. In particular, one siloxane exchange pathway has found to show behavior in useful temperature (180–220 °C) for its application vitrimers. The mechanism is involve 1,5,7-triazabicyclo [4.4.0] dec-5-ene (TBD) as an organic catalyst the presence hydroxyl groups. Using this new approach, ultrafast stress-relaxation characteristics (relaxation times below 10 s) prepared readily available epoxy resin and siloxane-amine hardener. Subsequently, low viscosity vitrimer enabled preparation glass fiber-reinforced composites industrially relevant vacuum-assisted infusion technique. resulting composite was successfully thermoformed into shape, which makes it possible envision second life such highly engineered materials.

Language: Английский

Citations

120
A Highly Dynamic Covalent Polymer Network without Creep: Mission Impossible? DOI
Filip Van Lijsebetten, Tapas Debsharma, Johan M. Winne

et al.

Angewandte Chemie International Edition, Journal Year: 2022, Volume and Issue: 61(48)

Published: Sept. 26, 2022

Dynamic covalent polymer networks provide an interesting solution to the challenging recyclability of thermosets and elastomers. One remaining design constraints, however, is balancing thermal reprocessability in form material flow with dimensional stability during use. As a result, many chemistries are being investigated order improve bond reactivity control robustness. This Minireview highlights number promising concepts, particular emphasis on disconnecting chemical low high temperature regimes obtain creep resistant, yet highly dynamic networks. In addition, we will highlight impact sharp changes when applying extrapolation-based approaches rheological analysis. confident that abandoning myth "permanent" aid development sustainable polymeric materials can truly combine benefits thermoplastic thermoset behaviour.

Language: Английский

Citations

93
Adhesion mechanism and application progress of hydrogels DOI
Zuobing Xiao, Qunfeng Li, Huiqin Liu

et al.

European Polymer Journal, Journal Year: 2022, Volume and Issue: 173, P. 111277 - 111277

Published: May 20, 2022

Language: Английский

Citations

82
3D printing of dynamic covalent polymer network with on-demand geometric and mechanical reprogrammability DOI Creative Commons
Zizheng Fang,

Yunpeng Shi,

Hongfeng Mu

et al.

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: March 10, 2023

Delicate geometries and suitable mechanical properties are essential for device applications of polymer materials. 3D printing offers unprecedented versatility, but the typically fixed after printing. Here, we report a photo-printable dynamic covalent network that can undergo two independently controllable bond exchange reactions, allowing reprogramming geometry Specifically, is designed to contain hindered urea bonds pendant hydroxyl groups. The homolytic between allows reconfiguring printed shape without affecting topology properties. Under different conditions, transformed into urethane via reactions with groups, which permits tailoring freedom reprogram in an on-demand fashion opportunity produce multiple products from one single step.

Language: Английский

Citations

48
Spiroborate-Linked Ionic Covalent Adaptable Networks with Rapid Reprocessability and Closed-Loop Recyclability DOI
Hongxuan Chen, Yiming Hu,

Chaoqian Luo

et al.

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(16), P. 9112 - 9117

Published: April 14, 2023

Covalent adaptable networks (CANs) represent a novel class of polymeric materials crosslinked by dynamic covalent bonds. Since their first discovery, CANs have attracted great attention due to high mechanical strength and stability like conventional thermosets under service conditions easy reprocessability thermoplastics certain external stimuli. Here, we report the example ionic (ICANs), type ionomers, consisting negatively charged backbone structures. More specifically, two ICANs with different compositions were prepared through spiroborate chemistry. Given nature linkages, resulting ionomer display rapid closed-loop recyclability mild conditions. The mechanically broken into smaller pieces can be reprocessed coherent solids at 120 °C within only 1 min nearly 100% recovery properties. Upon treating dilute hydrochloric acid room temperature, valuable monomers easily chemically recycled in almost quantitative yield. This work demonstrates potential bonds as linkage for development new reprocessable recyclable thermosets.

Language: Английский

Citations

45
Taking dynamic covalent chemistry out of the lab and into reprocessable industrial thermosets DOI
Stephan Maes, Nezha Badi, Johan M. Winne

et al.

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

Published: Jan. 31, 2025

Language: Английский

Citations

3
Reprocessing of Covalent Adaptable Polyamide Networks through Internal Catalysis and Ring-Size Effects DOI
Filip Van Lijsebetten,

Yann Spiesschaert,

Johan M. Winne

et al.

Journal of the American Chemical Society, Journal Year: 2021, Volume and Issue: 143(38), P. 15834 - 15844

Published: Sept. 15, 2021

Here, we report the introduction of internally catalyzed amide bonds to obtain covalent adaptable polyamide networks that rely on dissociation equilibrium between dicarboxamides and imides. While are usually considered be robust thermally stable, present study shows their dynamic character can activated by a smart choice available building blocks without addition any external catalyst or other additives. Hence, range polyamide-based with variable mechanical viscoelastic properties have been obtained in systematic study, using straightforward curing process dibasic ester amine compounds. Since involves cyclic imide formation, correlation ring size thermomechanical viscosity profile was studied for five- seven-membered intermediates, depending chosen monomer. This resulted marked temperature response activation energies 116–197 kJ mol–1, yielding sharp transition elastic viscous behavior. Moreover, ease versatility this chemistry platform were demonstrated selecting variety amines, resulting densely cross-linked Tg values ranging from −20 110 °C. With approach, it is possible design amorphous an acute response, allowing good reprocessability and, simultaneously, high resistance irreversible deformation at elevated temperatures.

Language: Английский

Citations

75
High-Tg and Degradable Isosorbide-Based Polybenzoxazine Vitrimer DOI Creative Commons
Antoine Adjaoud, Laura Puchot, Pierre Verge

et al.

ACS Sustainable Chemistry & Engineering, Journal Year: 2021, Volume and Issue: 10(1), P. 594 - 602

Published: Dec. 27, 2021

This work describes new fully bio-based vitrimers prepared from isosorbide, a renewable sugar-based chemical. Isosorbide was reacted with 4-hydroxypropionic acid, paraformaldehyde, mono-ethanolamine, and/or furfurylamine via consecutive solvent-free Fischer esterification and Mannich-like ring-closure reactions. The two-step synthesis led to the formation of di-telechelic benzoxazine-terminated isosorbide monomer, containing ester bonds aliphatic hydroxyl furan groups. atom economy factor yields 85%. structural features resulting products were substantiated by spectroscopic techniques. ring-opening polymerization monitored rheological differential scanning calorimetry (DSC) measurements. Very high Tg values afforded substructure measured (from 143 193 °C), which increase ring content. Internally catalyzed transesterification reactions conferred fast dynamic exchanges (τ* = 300 s at 180 °C). Self-healing chemical mechanical recycling also demonstrated. Finally, degradability polybenzoxazine demonstrated as well. materials highly stable in pH-neutral water, even 80 °C for 60 days, but owing structure, pronounced degradation observed under acidic or alkaline conditions. In summary, is suitable building block design degradable 100% recyclable high-Tg vitrimers.

Language: Английский

Citations

75
Controlling Dynamics of Associative Networks through Primary Chain Length DOI
Jacob J. Lessard, Kevin A. Stewart, Brent S. Sumerlin

et al.

Macromolecules, Journal Year: 2022, Volume and Issue: 55(22), P. 10052 - 10061

Published: Nov. 2, 2022

Dynamic networks couple the robust nature of thermosets with shapeability and recyclability thermoplastics. Though a wealth exchange chemistries can be leveraged to fabricate dynamic networks, reversibly cross-linked systems that are comprised primarily chains nonexchangeable backbones increase network complexity render flow behavior difficult predict. Here, we report polymethacrylate-based vitrimers prepared by cross-linking β-ketoester-containing polymers multifunctional amines demonstrate molecular weight dispersity primary tuned actively tailor dynamics resulting networks. Vitrimers similar composition cross-link density made from below well above entanglement exhibited distinct viscoelastic properties energies activation ranging 93 264 kJ/mol. Resistance creep increased dramatically increasing chain length. Finally, blending prepolymers skew Mn above/below Me was demonstrated, showing distinguishable effect prepolymer breadth skewness on vitrimer flow. Our results suggest tailoring chain-length distribution is viable strategy design materials predictable customizable behavior.

Language: Английский

Citations

51
Viscoelasticity of Polymers with Dynamic Covalent Bonds: Concepts and Misconceptions DOI
Murillo L. Martins, Xiao Zhao, Zoriana Demchuk

et al.

Macromolecules, Journal Year: 2023, Volume and Issue: 56(21), P. 8688 - 8696

Published: Nov. 3, 2023

Polymers with dynamic covalent bonds are an exciting class of materials properties and potential applications that rapidly gain significant attention from diverse scientific communities. While the number publications on this emerging topic increases exponentially, navigating through literature reveals a series physical inconsistencies in previously established concepts some misconceptions data analysis interpretation. The current paper presents practices often applied to characterization systems emphasizes particular may lead critical divergences misinterpretations results. We particularly focus should be avoided interpretation stress–relaxation viscoelastic estimates bond dissociation energy. Instead, we suggest using traditional approaches have been polymer for decades. Lastly, emphasize challenges full understanding microscopic behavior vitrimers.

Language: Английский

Citations

42