Insensitive Energetic Compounds Research Articles

Preparation, Crystal Structure and Properties of a New Crystal Form of Diammonium 5,5′‐bistetrazole‐1,1′‐diolate

AbstractA new crystal form of diammonium 5,5′‐bistetrazole‐1,1′‐diolate (1) was prepared by two novel methods and fully characterized by using IR, NMR spectroscopy, elementary analysis, single crystal X‐ray crystallography and thermal gravity/differential thermal analysis (TG/DTA). Crystalline 1 was found as monoclinic and space group of P21/c (14). The TG/DTA analysis showed that the decomposition temperature of 1 was 287.8°C with a mass loss of 91.2% in the range of 220–300°C at a heating rate of 5°C/min. The sensitivities test towards impact, friction of 1 indicated that 1 has much lower sensitivities than those of RDX/HMX and is comparable to those of TNT, which suggested that 1 could be used as a good candidate of new insensitive energetic compound.

A Simple and Efficient Route for Preparing 4-Chloro-3,5-Dinitropyrazole

4-Chloro-3,5-dinitropyrazole(ClDNP) as an insensitive energetic compound has been prepared with 4-Chloropyrazole(4-ClP)via nitrated by mixture of nitric acid and sulfuric acid. The reactionconditions were investigated, such as the molar ratio of 4-chloropyrazole and HNO3, reaction temperature, reaction time. Through the single factor experiment, the optimum reaction condition was determined that the molar ratio of 4-chloropyrazole and HNO3 was 1:4, the reaction time was 4h, the reaction temperature was 100-105°C. The yield of the ClDNP was up to 73.8% under the above conditions．The ClDNP was re-crystallization by methylbenzene.The target product was characterized by IR, 1H NMR, 13C NMR and Gauss Photography．

Fast Separation and Quantification Method for Nitroguanidine and 2,4-Dinitroanisole by Ultrafast Liquid Chromatography–Tandem Mass Spectrometry

Explosives are now persistent environmental pollutants that are targets of remediation and monitoring in a wide array of environmental media. Nitroguanidine (NG) and 2,4-dinitroanisole (DNAN) are two insensitive energetic compounds recently used as munitions explosives. To protect our environment and human health, the levels of these compounds in soils and waters need to be monitored. However, no sensitive analytical methods, such as liquid chromatography-tandem mass spectrometry (LC-MS/MS), have been developed for detecting these new compounds at trace levels and to be concurrently applied to monitor the common explosives. In general, the concentrations of explosives in either soil or water samples are very low and widely distributed. Therefore, a fast and sensitive method is required to monitor those compounds and increase our ability to find and address the threats they pose to human health and ecological receptors. In this study, a fast and sensitive analytical method has been developed to quantitatively determine NG and DNAN in soil, tap water, and river water by using ultrafast LC-MS/MS. To make this method a comprehensive analytical technique for other explosives as well, it has included other commonly used explosives in the method development, such as octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 1,3,5-trinitroper-hydro-1,3,5-triazine (RDX), 2,4,6-trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (ADNT), and pentaerythritol tetranitrate (PETN). The method detection limits (MDLs) of these compounds in soil ranged from 0.2 to 5 ppb, and a good linearity was obtained over a concentration range of 0.5-200 ppb. The recoveries of some compounds are equal to or better than the current EPA methods but with much higher sensitivities.

Bistetrazoles: Nitrogen-Rich, High-Performing, Insensitive Energetic Compounds

Large-scale syntheses of nitrogen-rich 5,5′-hydrazinebistetrazole (HBT) (or 1,2-ditetrazolylhydrazine) and bis(3,4,5-triamino-1,2,4-triazolium) 5,5′-azotetrazolate (G2ZT) with high yields and purities on a multigram scale are introduced. DSC analysis showed good thermal stabilities for both materials (>200 °C) and their long-term stabilities were assessed by TSC (thermal safety calorimetry). Because molecular structures play an important role in the properties of an energetic material, hydrogen bonding in both compounds is described in terms of graph-set analysis. The extensive hydrogen bonding in the structures seems to account for their relatively high densities (HBT, ρ = 1.841 g cm−3; and G2ZT, ρ = 1.708 g cm−3). The heats of combustion of the two compounds were calculated (ΔcU°(HBT) = −2396 cal g−1 and ΔcU°(G2ZT) = −2775 cal g−1) and combined with the experimentally determined densitites (X-ray) and the molecular formulas to calculate the detonation pressures (P) and velocities (D) using the EXPLO5 co...

Selection and Synthesis of Energetic Heterocyclic Compounds Suitable for Use in Insensitive Explosive and Propellant Compositions

AbstractThe rationale behind developing insensitive energetic compounds (IECs) for incorporation into insensitive munition (IM) formulations (rather than the alternative approach of desensitizing higher energy but sensitive compounds) is discussed. With the aim of selecting a maximum of 2–3 IECs suitable for use in insensitive explosive and propellant compositions, a survey of the literature on IECs published in the last 20 years was carried out. From around 50 candidates, a selection was made of eight prime candidates, all heterocyclic compounds (principally monocyclic or fused‐ring bicyclic compounds of the di‐ or triazine, triazole or oxadiazole classes), which displayed explosive performance significantly better than that of the ubiquitous IEC, TATB. The criteria for inclusion of compounds in these listings are described. Screening of the eight candidate compounds against further performance criteria reduced the list to five compounds which were evaluated in detail – these were: CL‐14 (5,7‐diamino‐4,6‐dinitrobenzofuroxan), ANPZ‐i (2,5‐diamino‐3,6‐dinitropyrazine), NNHT (2‐nitrimino‐5‐nitro‐hexahydro‐1,3,5‐triazine), NTAPDO (5‐nitro‐2,4,6‐triaminopyrimidine‐1,3‐dioxide), and PANT [4‐(picrylamino)‐5‐nitro‐1,2,3‐triazole]. A detailed analysis of scale‐up issues associated with each compound was then made, including cost and availability of precursors, hazards (chemical and explosive), effluent streams, and other scale‐up issues (e.g. materials of plant construction). A further downselection using these criteria gave the present short‐list comprising three compounds (the first three listed above) and further evaluation is in progress. The results of this study, funded by UK MOD, comprise the UK contribution to a nine‐nation European research collaboration in the EUCLID Common European Priority Area 14 “Energetic Materials”, as part of a five‐year project which commenced in October 2003.

Military High Explosives

Military high explosives are safe to handle, have a long shelf life, their energy density is high and the propagation of the explosion (detonation reaction) is very fast. The energetic compounds are combined with polymers and other substances to match the properties as required. To initiate a detonation, a shock wave is needed. This is accomplished with a small quantity of a primary explosive. Modern, extremely insensitive formulations have been developed in most countries to eliminate accidents with ammunition. Apart from insensitive energetic compounds, new inert or energetic binder systems will be introduced to improve the vulnerability. The search for new energetic materials with highest performance characteristics is a never-ending task.

2,6-Diamino-3,5-dinitro-1,4-pyrazine dimethyl sulfoxide solvate

The title compound, C4H4N6O4·C2H6OS, crystallizes in the triclinic space group P\overline 1. It is a di­methyl sulfoxide (DMSO) solvate of the insensitive energetic compound 2,6-di­amino-3,5-di­nitro-1,4-pyrazine (ANPZ). The structure has been determined to obtain more accurate metrical parameters for the 2,6-di­amino-3,5-di­nitro-1,4-pyrazine moiety than those obtained from unsolvated crystals which are invariably twinned. The packing motif consists of two formula units linked by strong complementary hydrogen bonds between the ANPZ units with the two DMSO solvate mol­ecules each linked by two bifurcated hydogen bonds to the two ANPZ units. This central motif is further linked into planar sheets by weaker interactions between the DMSO methyl H atoms and the O atoms from the nitro groups. This looser packing arrangement compared to ANPZ is reflected in a lower density (1.662 Mg m−3 versus 1.812 Mg m−3 for ANPZ).