Safer Pyrotechnic Obscurants Based on Phosphorus(V) Nitride

The potential of phosphorus(V) nitride, P 3 N 5  , as a replacement for red phosphorus, P R , in pyrotechnic obscurants has been theoretically and experimentally investigated. P 3 N 5 can be safely mixed with KNO 3 and even KClO 3 and KClO 4  . The corresponding formulations are surprisingly insensitive to friction and only mildly impact‐sensitive. P 3 N 5  /KNO 3 pyrolants with ξ =20–80 wt % P 3 N 5 burn 200 times faster than the corresponding mixtures based on P R and generate a dense smoke. Hence obscurants based on P 3 N 5  /KNO 3 have a figure of merit that by far exceeds that of current state‐of‐the‐art P R ‐based obscurants. Furthermore, unlike P R , which slowly degrades in moist air to phosphoric acids and phosphine (PH 3 ), P 3 N 5 is stable under these conditions and does not produce any acids or PH 3  . P 3 N 5 is hence a safe, stable, and powerful replacement for P R for use in insensitive munitions.