MXene-Engineered Multifunctional Epoxy Vitrimers: Uniting Self-Healing, Fire Safety, and Component Recyclability in Carbon Fiber Composites

The inherent irreversibility of conventional thermosets, such as epoxy resins, raises critical sustainability barriers in structural composites, where catastrophic in-use repairing, fire retarding, and end-of-life recycling remain mutually exclusive. Here, we address this trilemma via MXene-engineered epoxy vitrimers and their carbon fiber composites, synergizing polydopamine-functionalized MXene (MXP) with flame-retardant-functionalized dynamic transesterification chemistry. Beyond nondestructive recycling of the carbon fibers therein, this study further demonstrates the recyclability of MXP, enhancing the sustainability and economic viability of the composite. The material demonstrates triply precision healing through localized near-infrared light (78.5% efficiency at 0.18 W cm–2), low-voltage electricity (86.7% at 4.5 V), and conventional thermal stimuli (76.1% at 180 °C), coupled with phosphorus chemistry and MXene shielding that reduce peak heat release and total smoke during burning by 39.3% and 38.9%, respectively. Remarkably, closed-loop recycling recovers carbon fiber and MXene after mild solvolysis, allowing component recyclability without a performance compromise. This systemic integration of multifunctionality and material circularity redefines sustainable, reliable, and durable composite design while uniting full-component recyclability─a critical leap toward circular structural materials.