Supramolecular Nanoclusters Enable High-Performance and Recyclable Epoxy Resins

Area of Science:

• Materials Science
• Polymer Chemistry
• Composite Materials

Background:

• Epoxy resins are crucial for high-performance composites but face challenges in balancing mechanical properties with recyclability.
• Current strategies often struggle to achieve both superior performance and environmental sustainability in epoxy thermosets.

Purpose of the Study:

• To develop a novel supramolecular nanocluster (SNs) strategy for epoxy resins.
• To simultaneously enhance mechanical properties and achieve recyclability in epoxy-based composites.

Main Methods:

• Synthesized SNs using cationic polymerization initiated by a Zn²⁺-based liquid coordination complex.
• Incorporated SNs into a cross-linked epoxy network, leveraging metal-coordination, hydrogen bonding, and flexible polyether chains.
• Utilized embedded Zn²⁺ sites as catalysts for resin hydrolysis.

Main Results:

• Optimized epoxy resin exhibited a tensile strength of 134 MPa, a modulus of 4.9 GPa, and a 49% increase in fracture toughness.
• Carbon fiber-reinforced composites showed enhanced tensile and flexural performance.
• Achieved complete resin hydrolysis within 6 hours at 170°C in water, with products repurposed as sizing agents.

Conclusions:

• The SNs strategy effectively reconciles the performance-sustainability trade-off in epoxy thermosets.
• Demonstrated a viable recyclable pathway for high-performance epoxy composites.
• The developed materials offer a sustainable alternative for advanced composite applications.