Recent Advances in Vitrimers and Advanced Composites: Sustainable Synthesis, Reprocessing, Welding, and Applications

Covalent Adaptable Networks (CANs), particularly vitrimers, represent an innovative class of polymers that combine the durability of thermosets with the recyclability of thermoplastics. Unlike conventional thermosets, vitrimers feature dynamic covalent bonds that allow reversible exchange reactions, typically triggered by heat. This enables network rearrangement while preserving crosslinked integrity, granting vitrimers unique properties like reprocessability, self-healing, and welding. Welding occurs through stress relaxation, bond exchange, and chain diffusion, forming new covalent linkages. Key dynamic chemistries include transesterification (e.g., in epoxy-anhydride systems), imine exchange, and disulfide metathesis. Growing research focuses on sustainable bio-based vitrimers derived from renewable sources like soybean oil, eugenol, and cardanol. Their blend of strength and adaptability makes them ideal for applications such as recyclable adhesives, flexible electronics (e.g., sensors), and 3D printing, positioning vitrimers as a promising solution for sustainable, high-performance materials.

Traditional thermoset polymers pose a significant environmental challenge due to their permanent crosslinked networks, which prevent recycling and contribute to waste accumulation. To address this, researchers are developing Covalent Adaptable Networks (CANs), particularly vitrimers, which incorporate dynamic covalent bonds that enable reversible exchange reactions under thermal or photochemical stimuli. This innovation allows vitrimers to retain the durability of thermosets while gaining thermoplastic-like reprocessability, enabling recycling, self-healing, and welding capabilities. Recent advances focus on expanding dynamic chemistries beyond transesterification to include disulfide, imine, and boronic ester exchanges, while simultaneously developing bio-based vitrimers from renewable resources like plant oils and lignin derivatives to enhance sustainability. Processing techniques such as 3D printing and advanced welding methods are being optimized to leverage vitrimers' unique properties for manufacturing complex, recyclable structures. Additionally, their stimuli-responsive nature makes them promising for flexible electronics and sensors. Fundamental studies using molecular simulations and catalytic design further elucidate bond-exchange mechanisms to tailor material performance. By combining these approaches, vitrimers bridge the gap between traditional thermosets and thermoplastics, offering a pathway toward sustainable, high-performance materials that support circular economy principles while maintaining the robustness required for industrial applications.

The innovation lies in dynamic covalent bonds that enable reversible exchange reactions under stimuli like heat or light, allowing network rearrangement while preserving crosslink density. This imparts vitrimers with reprocessability, self-healing, shape memory, and welding capabilities.

Key research themes include:

-Dynamic Chemistries: Transesterification, disulfide/imine exchange, and siloxane metathesis are explored to tailor properties.

-Bio-based Vitrimers: Sustainable feedstocks (e.g., plant oils, vanillin) reduce reliance on fossil fuels.

-Sustainable advanced composites: Manufacturing and characterization of vitrimeric composites and nanocomposites;

-Welding Techniques: Methods like Induction or ultrasonic welding leverage bond exchange for component repair/assembly.

-Advanced Manufacturing: Vitrimers are integrated into 3D printing (DLP, FFF) for recyclable, high-resolution structures.

-Functional Applications: Their adaptability suits flexible electronics, sensors, and actuators.

-Fundamental Insights: Simulations (MD, MC) and catalysis studies optimize bond exchange kinetics and material design.

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Article types

This Research Topic accepts the following article types, unless otherwise specified in the Research Topic description:

• Editorial
• FAIR² Data
• FAIR² DATA Direct Submission
• Mini Review
• Original Research
• Perspective
• Review

Keywords: Covalent Adaptable Networks (CANs), Vitrimers, Bio-based polymers, Self-healing materials, 3D/4D printing, Circular economy, Plastic welding, Flexible electronics, Sustainable Composites, Viscoelastic behavior

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