Bio-based host-guest complex enabling MXene towards multifunctional fire-safe epoxy via confined catalysis

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• High-performance epoxy resins are crucial for demanding applications like aviation and coatings.
• Developing fire-safe, mechanically robust, and multifunctional polymers remains a significant challenge.
• Existing flame retardants often involve hazardous elements and can compromise material properties.

Purpose of the Study:

• To engineer a novel, multi-functional epoxy composite with enhanced fire safety and mechanical robustness.
• To explore a bio-based host-guest ferrocene chemistry for confined MXene assembly.
• To achieve high fire-retardant efficiency without conventional flame-retardant elements.

Main Methods:

• Synchronous intercalation and surface assembly of MXene using bio-based host-guest ferrocene chemistry.
• Incorporation of the synthesized hybrid MXene@CD@Ferr-Fe into an epoxy matrix at ultralow loading (2 wt%).
• Evaluation of fire safety (UL-94 V-0, LOI, heat release rate, smoke production), mechanical properties, thermoelectric sensitivity, photothermal conversion, and degradability.

Main Results:

• Achieved UL-94 V-0 rating, limiting oxygen index of 29.5%, and significant reductions in peak heat release rate (40.3%) and smoke production (42.0%).
• Demonstrated visibly improved mechanical properties.
• Exhibited a thermoelectric fire alarming feature within 3 seconds (Seebeck coefficient ~6.3 μV/K) and enhanced photothermal conversion (45°C increase in 300s).
• Showcased an 82 wt% degradation rate within 11 hours in a mild co-solvent due to confined ferrocene catalysis.
• Mechanism revealed a dual-mode iron catalytic charring reaction.

Conclusions:

• The P/N/Si-free confined catalytic engineering strategy provides a novel approach for high fire-retardant efficiency.
• The developed epoxy composite exhibits excellent fire safety, mechanical strength, and multi-functionality.
• This work expands the application of ferrocene chemistry to 2D materials for advanced polymer design.