Enabling the Reprocessability and Debonding of Epoxy Thermosets Using Dynamic Poly(β‐Amino Amide) Curing Agents DOI Open Access
Loc Tan Nguyen, Stephan Maes, Filip Du Prez

et al.

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 30, 2024

Abstract Epoxy resins, by showing outstanding performances, stand out as the most applied materials in thermoset products. However, their excellent properties, associated with covalently cross‐linked structures, come at expense of recyclability, thus posing environmental and regulatory challenges. Herein, starting from recently explored reversibility robust poly(β‐amino amide)s, dynamic curing agents are synthesized a one‐pot procedure for use preparation epoxy‐derived networks. The obtained retain desirable properties while being fully (re)processable, high temperature‐dependent viscoelasticity (activation energy (E ) ≈230 to 270 kJ mol −1 ). Moreover, this new generation epoxy shows resistance hydrolysis creep elevated temperatures (up 120 °C). As an entry point further applications, reversible implemented adhesive formulations, showcasing lap shear strengths that comparable commercial hardeners 9 MPa). β‐amino amide groups provide adhesives additional functionality heat‐triggered deconstruction (130 150 °C), re‐bonding capacity up 80% recovery lap‐shear strength. To encourage industrial adoption, cost‐effective, drop‐in synthesis protocol is developed using only bulk chemicals, hence facilitating practical implementation.

Language: Английский

Epoxy Vitrimer with Excellent Mechanical Properties and High Tg for Detachable Structural Adhesives DOI
Anping Dong,

Qiguang Liu,

Huarui Yao

et al.

ACS Applied Materials & Interfaces, Journal Year: 2025, Volume and Issue: 17(9), P. 14578 - 14590

Published: Feb. 22, 2025

It is a long-standing challenge for thermoset resins to simultaneously achieve outstanding thermomechanical and mechanical properties as well rapid network reconfiguration due the trade-off between chemical bond transformation stability of network. The design vitrimer topology an effective strategy address above issues. Here, we prepared epoxy material (DGEBA-API-MHHPA) with excellent high glass-transition temperature (Tg) by introducing rigid-flexible integrated side chains [1-(3-aminopropyl) imidazole (API)], which endow DGEBA-API-MHHPA multiple interactions including "internal antiplasticization" effect, intermolecular hydrogen bonds, π-π interactions. Moreover, introduction Zn2+ facilitates transesterification, enabling fast rearrangement Specifically, relaxation time DGEBA-API0.2-MHHPA0.8-Zn reaches 65 s at 200 °C. Meanwhile, Zn2+-imidazole coordination bonds energy dissipation improve toughness resulting exhibits self-healing recyclable behaviors possesses 80.3 MPa tensile strength, 3.25 GPa Young's modulus, 7.2 MPa·m1/2 fracture (KIC), Tg 129 Concurrently, can be applied detachable structural adhesives various substrates used matrixes electrically composites. This skillful widely referenced in large-scale manufacturing high-performance dynamic covalent their composites performance.

Language: Английский

Citations

1
Self-healing materials based on dynamic properties of siloxane networks DOI Creative Commons
Taiki Hayashi, Atsushi Shimojima

Journal of Sol-Gel Science and Technology, Journal Year: 2025, Volume and Issue: unknown

Published: April 7, 2025

Language: Английский

Citations

0
Covalent Adaptable Networks with Associative Siloxane Exchange Enabled by Amide‐Based Internal Catalysis: Designing for Reprocessability and Extrudability by Increasing the Cross‐Link Density DOI Creative Commons
Nathan S. Purwanto, Tong Wang, Xiaoyang Liu

et al.

Advanced Functional Materials, Journal Year: 2025, Volume and Issue: unknown

Published: May 9, 2025

Abstract Replacing non‐recyclable thermosets with covalent adaptable networks (CANs) that recover cross‐link density after reprocessing will reduce waste and contribute to a circular polymer economy. Many CANs undergoing associative dynamic exchange require catalysis. External catalysis often leads harmful effects, e.g., increased creep, accelerated material aging, catalyst leaching. Herein, internally catalyzed siloxane chemistry is demonstrated resulting from amides covalently linked through alkyl chains siloxanes. Small‐molecule studies show the formation of products reaction two amide‐containing molecules. From rubbery plateau modulus, each siloxane‐exchange‐based CAN exhibits temperature‐invariant, or nearly so, characteristic CANs. The length in siloxane‐containing monomer tunes network density. Cross‐link recovery achieved, required time temperature decreasing increasing Stress relaxation also faster dynamics reprocessability arise because second order (i.e., cross‐linker) concentration. Capitalizing on this, melt extrusion highest demonstrated, achieving same extruded compression‐molded Using identical conditions, next‐highest not extrudable.

Language: Английский

Citations

0
Investigation on Polyether Sulfone Toughening Epoxy Vitrimer: Curing and Dynamic Properties DOI Open Access
Xiang Liu, Mei Lan Fang, Yuezhan Feng

et al.

Macromolecular Rapid Communications, Journal Year: 2024, Volume and Issue: 45(23)

Published: Oct. 7, 2024

Abstract Diglycidyl ether of bisphenol A crosslinking with glutaric anhydride is used to form the conventional “covalent adaptive network”, polyether sulfone (PES) by coiling and aggregating on network significantly increase uncured resin viscosity for improving processability epoxy resin, but inevitably affecting curing reaction dynamic transesterification reaction. This study investigates crucial roles PES in dynamics stress relaxation behavior. The results indicate that although does not directly participate polyester‐based vitrimers. Moreover, isothermal studies reveal addition can greatly bring forward rate peak from conversion α = 0.6 0.2, meaning mechanism transfers chemical control diffusion control. Dynamic property analysis shows accelerates relaxation, especially at lower temperatures, leading low viscous flow activation energy E τ relatively insensitive behavior temperature. Introducing into vitrimer improves density (2.31 × 10⁴ mol m − 3 ), enhancing glass transition temperature (82.68 °C), tensile strength (68.66 MPa), fracture toughness (6.25%). Additionally, modified exhibits satisfying shape memory performance reprocessing capability.

Language: Английский

Citations

3
Enabling the Reprocessability and Debonding of Epoxy Thermosets Using Dynamic Poly(β‐Amino Amide) Curing Agents DOI Open Access
Loc Tan Nguyen, Stephan Maes, Filip Du Prez

et al.

Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 30, 2024

Abstract Epoxy resins, by showing outstanding performances, stand out as the most applied materials in thermoset products. However, their excellent properties, associated with covalently cross‐linked structures, come at expense of recyclability, thus posing environmental and regulatory challenges. Herein, starting from recently explored reversibility robust poly(β‐amino amide)s, dynamic curing agents are synthesized a one‐pot procedure for use preparation epoxy‐derived networks. The obtained retain desirable properties while being fully (re)processable, high temperature‐dependent viscoelasticity (activation energy (E ) ≈230 to 270 kJ mol −1 ). Moreover, this new generation epoxy shows resistance hydrolysis creep elevated temperatures (up 120 °C). As an entry point further applications, reversible implemented adhesive formulations, showcasing lap shear strengths that comparable commercial hardeners 9 MPa). β‐amino amide groups provide adhesives additional functionality heat‐triggered deconstruction (130 150 °C), re‐bonding capacity up 80% recovery lap‐shear strength. To encourage industrial adoption, cost‐effective, drop‐in synthesis protocol is developed using only bulk chemicals, hence facilitating practical implementation.

Language: Английский

Citations

1