A Novel Cocrystal Explosive of HNIW with Good Comprehensive Properties

Abstract

In order to improve the safety of the high explosive 2,4,6,8,10,12‐hexanitrohexaazaisowurtzitane (HNIW), we cocrystallized HNIW with the insensitive explosive DNB (1,3‐dinitrobenzene) in a molar ratio 1 : 1 to form a novel cocrystal explosive. Structure determination showed that it belongs to the orthorhombic system with space group Pbca. Therein, layers of DNB alternate with bilayers of HNIW. Analysis of interactions in the cocrystal indicated that the cocrystal is mainly formed by hydrogen bonds and nitro‐aromatic interactions. Moreover, the thermal behavior, sensitivity, and detonation properties of the cocrystal were evaluated. The results implied that the melting point of the cocrystal is 136.6 °C, which means an increase of 45 °C relative that of pure DNB. The predicted detonation velocity and detonation pressure of the cocrystal are 8434 m s−1 and 34 GPa, respectively, which are similar to that of the reported HNIW/TNT cocrystal, but its reduced sensitivity (H50=55 cm) makes it an attractive ingredient in HNIW propellant formulations.

A novel cocrystal explosive NTO/TZTN with good comprehensive properties

“…7,8 However, achieving a ne balance between high detonation performance and low sensitivity is challenging task, as the energy and sensitivity of explosives usually conict with each other, few of these materials have proven suitable for explosives application. [12][13][14][15] Co-crystallization is an effective method to improve the solubility, bioavailability physical and chemical stability properties of drugs without changing their chemical structure, and it is widely used for the pharmaceutical chemicals. [12][13][14][15] Co-crystallization is an effective method to improve the solubility, bioavailability physical and chemical stability properties of drugs without changing their chemical structure, and it is widely used for the pharmaceutical chemicals.…”

Molecular Dynamics Simulation Studies of the CL-20/DNB Co-crystal

“…Based on the crystal parameters derived from X-ray diffraction [24,25,14], three primary simulation cells containing individually 72, 160 and 96 molecules, equivalent to 2592, 2560 and 2496 atoms, were used for the ε-CL-20, DNB crystals and the CL-20/DNB co-crystal, corresponding to 18 (2×3×3), 40 (2×2×10) and 6 (3×2×1) unit cells, respectively. In the co-crystal, the numbers of CL-20 and DNB molecules were both 48.…”

“…For the current single compound explosives, high performance and safety are somewhat mutually exclusive, which seriously limits their development and applications [2]. Fortunately, the recent formation of energetic co-crystals [3][4][5][6][7][8][9][10][11][12][13][14] offers opportunities to modify the properties of energetic materials, such as oxygen balance, sensitivity, detonation velocity, and safety. A co-crystal [16,17] is a multiple component crystal that is constructed from two or more neutral molecular components, which co-exist at an intrinsic stoichiometric ratio by non-covalent interactions (such as hydrogen bonding, van der Waals, and π-π stacking interactions, etc.…”

“…In this paper, we have studied a CL-20/DNB co-crystal, where the molar ratio is 1:1. This CL-20/DNB co-crystal features much better insensitivity and makes it a promising ingredient in CL-20 propellant formulations [14]. For comparison, a CL-20/DNB composite with the same molar ratio as its co-crystal, ε-CL-20 and DNB crystals were also considered.…”

“…However, the ε-CL-20 crystal has also failed to meet the high demands of safety for modern ordnance due to its high sensitivity. Recently, researchers have attempted to reduce the sensitivity of ε-CL-20 crystals via the strategy of co-crystallization [5,[10][11][12][13][14][15], which reduces the sensitivity of ε-CL-20 crystals without a significant decrease in its energy performance. DNB (1, 3-dinitrobenzene, Figure 1b) is even more insensitive than TNT (2,4,6-trinitrotoluene), and is a well-known insensitive explosive [14,21].…”