Synthesis of Nitrogen‐Rich Black Phosphorus via a Diazotization Strategy for Efficient Flame Retardancy and Mechanical Properties of Epoxy Resins.

Severe flame retardancy and poor impact resistance of epoxy resins (EPs) have become key factors limiting their industrial application. Herein, a strategy is developed to integrate nitrogen‐rich black phosphorus (BP) loaded with cerium oxide via aryl diazonium chemistry to reduce the flame risk of the EPs. Cone test results exhibit that the fire hazard of EPs containing 2 wt.% BP‐NHH‐Ce is suppressed effectively, such as that total heat release rate (THR) is reduced by 46.9%, the peak heat release rate (pHRR) is reduced by 56.2%, and the total smoke production (TSP) is reduced by 48.9%. With only 1.0 wt.% of the BP‐NHH‐Ce added, the nanocomposite can reach up to 30.5 of LOI value and simultaneously upgrade the UL‐94 rate to V‐0. In addition, the nano‐structure is beneficial to stress transfer and homogenization, which leads to significant elevation (28.2%) for the impact strength of EPs. This developed new EP/BP‐NHH‐Ce nanocomposite merits the high‐end field application of EPs. [ABSTRACT FROM AUTHOR]