Detonation of high explosives containing phosphorus(V) nitride, P3N5

Abstract

AbstractComposition A4 (RDX/wax, 94/6 wt %) modified with additional phosphorus(V) nitride, P3N5 (CAS‐No.: [12136‐91‐3]) and aluminum does not show increased detonation velocity, Gurney energy or blast pressure when compared with the baseline formulation. The general failure of P3N5 to contribute to the detonation performance is understood to result from the low negative enthalpy of formation of P3N5 that makes this compound a “heat sink” in the detonation and post detonation zone. A formulation containing both P3N5 and Al (RDX/P3N5/Al/wax: 50.76/36/10/3.24 wt %) shows superior luminosity and temperature of the post detonation fireball when compared with both Comp A4 and even aluminized Comp A4 (Hexal=RDX/Al/wax: 65.8/30/4.2 wt %). The superior luminosity is understood to be due to formation of aluminum phosphate, AlPO4 a material with high optical emissivity which however, decomposes above T=1600 °C.