Respirator-inspired shielding and catalytic oxidation strategies for smoke-suppression polymers, enhancing fire safety†

Abstract

Polymeric materials pose potential fire hazards to both humans and property because of their intrinsic flammability and the toxic smoke generated by them upon burning. Lowering the risk by relying on traditional firefighting approaches is not timely and sufficient. Herein, analogous to wearing intelligent and responsive respirators, we introduced a universal smoke-suppression and flame-retardant strategy for flammable materials by forming a shield for protection and catalytic oxidation of smoke. Incorporating ethylenediaminetetraacetic acid tripotassium salt dihydrate (EDTA-K₃·2H₂O) into FPUF promotes rearrangement and cross-linking into char in the condensed phase during fire exposure. Additionally, the resulting alkali metal species act as active catalysts to further oxidize smoke, enhancing fire safety performance. Taking flexible polyurethane foam (FPUF) as an example, even in the absence of traditional flame-retardant elements, this foam demonstrates a significant reduction in specific smoke density (−54%) and total smoke release (−45%) for flexible polyurethane foam (FPUF), a high limiting oxygen index of 26.1%, rapid self-extinguishing performance, and robust overall mechanical properties. Moreover, this work offers exceptional fire protection for epoxy resin and waterborne polyurethane as well. Our work provides a facile strategy inspired by the protection of a respirator for high-performance firefighting.