Conceptually Novel Few-Layer Black Phosphorus/Supramolecular Coalition: Noncovalent Functionalization Toward Fire Safety Enhancement

Black phosphorus (BP) has been widely concerned in the field of composite materials because of its special geometrical and physicochemical properties. As a red phosphorus allotrope, BP has the dual function of physical barrier and catalytic carbonization and has the potential to be a highly effective flame retardant. In this article, the aminated BP/melamine cyanurate (BP–NH–MCA) coalition with a sandwich structure was prepared by an in situ self-assembly of MCA supramolecules on the surface of aminated BP. TEM, SEM, and the surface distribution scan results showed that the hybrid nanosheets were successfully fabricated and uniformly distributed in the matrix. The analysis of the data of cone calorimetry showed that with the loading of BP–NH–MCA increasing from 0.5 to 2.0 wt %, the peak value of heat release rate of composites decreases by 21.9–47.2%, and the total heat release value decreases by 26.7–42.3%. In addition, the EP/BP–NH–MCA2.0 nanocomposite has the lowest emission intensity of typical volatile products, including toxic CO during combustion, compared to EP/BP2.0 and pure EP samples, significantly improving the fire safety of composites. This work provides a reference for the application of BP in flame-retardant fields and reveals the flame-retardant mechanism of its hybrid materials.