Microbranching-Stabilized Dynamic Epoxy Networks for Rapid-Curing, Mechanically Robust, and Upcyclable Thermosets

Area of Science:

• Materials Science
• Polymer Chemistry
• Composite Manufacturing

Background:

• Rapid curing in epoxy thermosets is crucial for scalable manufacturing but often leads to poor homogeneity and mechanical properties.
• Limited reusability and recyclability of conventional thermosets pose environmental and economic challenges.

Purpose of the Study:

• To develop a microbranching-stabilized dynamic epoxy network for rapid curing, enhanced mechanical performance, and upcycling.
• To investigate the relationship between network architecture, morphology, and material properties.
• To demonstrate the reprocessability and recyclability of the developed epoxy thermoset.

Main Methods:

• Synthesis of a microbranched amine curing agent (Gm-12) for homogeneous blending with epoxy monomers.
• Characterization of the epoxy network (DGm-12) morphology, mechanical properties (tensile strength, fracture toughness), and curing kinetics.
• Incorporation of dynamic ester and disulfide bonds to enable network rearrangement and degradation.

Main Results:

• Achieved complete curing within 10 minutes at 150°C using the Gm-12 curing agent.
• Developed an epoxy network (DGm-12) with a microphase-separated morphology, exhibiting a tensile strength of 88 MPa and fracture toughness of 3.5 MPa·m^1/2.
• Demonstrated full reprocessability, including reuse of prepregs, reshaping of cured composites, and recovery of carbon fibers via hydrothermal degradation.

Conclusions:

• The microbranching-stabilized dynamic epoxy network reconciles rapid curing with high mechanical performance and recyclability.
• This approach provides a design principle for advanced thermosets with improved sustainability and manufacturing efficiency.
• The developed material offers a viable solution for upcycling epoxy composites, reducing waste and enabling resource recovery.