New NHNO2 substituted borazine-based energetic materials with high detonation performance

Abstract

Electrostatic potential analysis of molecular surface with the aid of B3LYP, B3PW91 and M06-2X density functional methods was used to estimate the crystal density and enthalpy of sublimation of a series of borazine-based energetic compounds containing nitramino (–NHNO2) substituent. The calculated enthalpy of sublimation was combined with the gas phase enthalpy of formation to predict the solid phase enthalpy of formation. These data in conjugation with the molecular composition of mentioned compounds were used for evaluating the detonation characteristics using Becker–Kistiakowsky–Wilson (BKW) equation of state. The crystal density, detonation velocity and detonation pressure of nitraminoborazines are in the range of 1.373–1.832g/cm3, 7274–7851m/s and 215–261 kbar, respectively. The enthalpies of formation of these compounds are negative, which indicate high thermodynamic stability of nitraminoborazines. Addition of –NHNO2 group to B-substituted borazines including –NO2 and –N3 groups increases the thermodynamic stability of desired compound, whereas they have reverse effect on the N-substituted ones. The molecular structure of novel –NHNO2 substituted borazine-based high energy materials containing –N3 groups with greater performance than conventional organic nitramines i.e. tetryl, DNNT, DANT, RDX and HMX, were also presented. These compounds have high detonation velocity, i.e. near 10,000m/s.