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

A fire-safe and mechanically robust epoxy with multi-functionality is in great demand in various fields such as aviation and functional coatings. To attain this goal, a bio-based host-guest ferrocene chemistry coupled with complexation reaction drove a confined intercalation and surface assembly of MXene synchronously. Without conventional fire-retardant elements, a ultralow loading of 2 wt% as-synthesized hybrid MXene@CD@Ferr-Fe endowed epoxy with UL-94 V-0 rating, limiting oxygen index of 29.5 %, a reduced peak heat release rate and smoke production rate by 40.3 % and 42.0 %, respectively. Moreover, the mechanical property was improved visibly. Of note, the redox reaction of ferrocene favored stronger thermoelectric sensitive fire alarming feature in 3 s with Seebeck coefficient of about 6.3 μV/K. Additionally, EP/MXene@CD@Ferr-Fe displayed an improved photothermal conversion capacity with an increasing temperature of 45 °C over 300 s. After ending of the life, EP/MXene@CD@Ferr-Fe possessed a 82 wt% degradation rate within 11 h in a mild CH₃COOH/H₂O₂ co-solvent due to confined ferrocene catalysis. A mechanism investigation involved in a dual-mode iron catalytic charring reaction at a confined state. This work provided a P/N/Si-free novel confined catalytic engineering strategy to realize a higher fire-retardant efficiency. Also, this work expanded ferrocene chemistry border to 2D materials in the design of high-performance, multifunctional fire-safe polymers.