Characteristics of Melt Cast Compositions Based on cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d] imidazole (BCHMX)/TNT

Abstract

cis-1,3,4,6-Tetranitrooctahydroimidazo-[4,5 d]imidazole (BCHMX) is a new bicyclic nitramine which has been prepared using a two-stage synthetic method. In this work, a new melt cast composition based on BCHMX/TNT (60/40 by wt.) was prepared. For comparison purposes, Composition B based on RDX (1,3,5-trinitro1,3,5-triazacyclohexane)/TNT (60/40 by wt.), and HMX (1,3,5,7-tetranitro-1,3,5,7tetraazacyclooctane)/TNT (60/40 by wt.) were also studied. Impact and friction sensitivities of these compositions and of the individual explosives were determined. The detonation velocities were measured experimentally. The performance of the compositions prepared was studied by measuring the brisance using the Kast method. The detonation parameters of the compositions and the individual explosives were calculated using the EXPLO5 thermodynamic code. The results show that mixing these nitramines with TNT decreases their sensitivities. BCHMX/TNT is more sensitive to impact and friction than Composition B while it has higher detonation parameters, at the same level as HMX/TNT. In comparison, BCHMX/TNT has the highest relative brisance of the compositions studied. It is postulated that the higher performance characteristics of BCHMX and compositions based on it, in comparison with those of HMX, are due to a higher positive heat of formation for this nitramine.