共查询到20条相似文献，搜索用时 15 毫秒
1.
Thomas&#x;M. Klaptke Konstantin Karaghiosoff Peter Mayer Alexander Penger Jan&#x;M. Welch 《Propellants, Explosives, Pyrotechnics》2006,31(3):188-195
1,4‐Dimethyl‐5‐aminotetrazolium 5‐nitrotetrazolate ( 2 ) was synthesized in high yield from 1,4‐dimethyl‐5‐aminotetrazolium iodide ( 1 ) and silver 5‐nitrotetrazolate. Both new compounds ( 1, 2 ) were characterized using vibrational (IR and Raman) and multinuclear NMR spectroscopy (1H, 13C, 14N, 15N), elemental analysis and single crystal X‐ray diffraction. 1,4‐Dimethyl‐5‐aminotetrazolium 5‐nitrotetrazolate ( 2 ) represents the first example of an energetic material which contains both a tetrazole based cation and anion. Compound 2 is hydrolytically stable with a high melting point of 190 °C (decomposition). The impact sensitivity of compound 2 is very low (30 J), it is not sensitive towards friction (>360 N). The molecular structure of 1,4‐dimethyl‐5‐aminotetrazolium iodide ( 1 ) in the crystalline state was determined by X‐ray crystallography: orthorhombic, Fddd, a=1.3718(1) nm, b=1.4486(1) nm, c=1.6281(1) nm, V=3.2354(5) nm3, Z=16, ρ=1.979 g cm−1, R1=0.0169 (F>4σ(F)), wR2 (all data)=0.0352. 相似文献
2.
Richard Turcotte Phillip&#x;D. Lightfoot Christopher&#x;M. Badeen Marie Vachon David&#x;E.&#x;G. Jones Sek&#x;Kwan Chan 《Propellants, Explosives, Pyrotechnics》2005,30(2):118-126
It is well known that water‐based commercial explosives locally ignited in closed vessels do not undergo self‐sustained combustion when the pressure is lower than some threshold value. The latter is usually referred to as the Minimum Burning Pressure (MBP) of the explosive and is now being used by some manufacturers as a basis of safety for many associated manufacture, transport, and handling processes. In the present work, both an apparatus based on hot‐wire ignition and an associated methodology were developed to measure the MBP of water‐based explosives. Typical results for various emulsion and water‐gel explosives are also reported and discussed. It is also shown that the technique could be used to characterize very insensitive explosive substances normally used as explosive precursors. 相似文献
3.
Richard Turcotte Sandra Goldthorp Christopher&#x;M. Badeen Sek&#x;Kwan Chan 《Propellants, Explosives, Pyrotechnics》2008,33(6):472-481
Emulsions based on ammonium nitrate (AN) and water locally ignited by a heat source do not undergo sustained combustion when the pressure is lower than some threshold value usually called the Minimum Burning Pressure (MBP). This concept is now being used by some manufacturers as a basis of safety. However, before a technique to reliably measure MBP values can be designed, one must have a better understanding of the ignition mechanism. Clearly, this is required to avoid under ignitions which could lead to the erroneous interpretation of failures to ignite as failures to propagate. In the present work, facilities to prepare and characterize emulsions were implemented at the Canadian Explosives Research Laboratory. A calibrated hot‐wire ignition system operated in a high‐pressure vessel was also built. The system was used to study the ignition characteristics of five emulsion formulations as a function of pressure and ignition source current. It was found that these mixtures exhibit complicated pre‐ignition stages and that the appearance of endotherms when the pressure is lowered below some threshold value correlates with the MBP. Thermal conductivity measurements using this hot‐wire system are also reported. 相似文献
4.
Richard Turcotte Sandra Goldthorp Christopher&#x;M. Badeen Hongtu Feng Sek&#x;Kwan Chan 《Propellants, Explosives, Pyrotechnics》2010,35(3):233-239
It has been well established that sustained combustion in ammonium nitrate water‐based emulsions (AWEs) can only occur if the ambient pressure is held above some threshold value, usually referred to as the ‘minimum burning pressure’ (MBP). For the commercial explosives industry, a good knowledge of the MBP for particular AWE formulations is essential to estimate safe operating pressures for the associated manufacturing and handling processes. In these processes, AWE products are most often pumped in closed systems and at elevated temperature. While previous studies have established that the MBP can depend critically on major ingredients, its dependence on physical characteristics such as temperature and viscosity had never been investigated. Moreover, the consequences of alterations in measurement methodologies on the resulting measured MBP values had not been studied. 相似文献
5.
Gregory&#x;W. Drake Tommy&#x;W. Hawkins Jerry Boatz Leslie Hall Ashwani Vij 《Propellants, Explosives, Pyrotechnics》2005,30(2):156-163
The synthesis and characterization of 1,5‐diamino‐1,2,3,4‐tetrazolium perchlorate were carried out. Experimental evidence strongly supports the protonation of a nitrogen atom of the tetrazole ring, including the structure observed in a single crystal X‐ray diffraction study of the title compound. Quantum chemical calculations were performed at the CCSD(T)/6‐311G(2df, p)//MP2/6‐311G(d, p) level of theory to determine the relative energies of all possible N‐protonated structures of the 1,5‐diamino‐1,2,3,4‐tetrazole ring. The predicted geometry of the most stable isomer compares favorably with the experimentally observed structure. 相似文献
6.
Janna Geith Thomas&#x;M. Klaptke Jan Weigand Gerhard Holl 《Propellants, Explosives, Pyrotechnics》2004,29(1):3-8
The enthalpies of combustion (ΔcombH) of dinitrobiuret (DNB) and diaminotetrazolium nitrate (HDAT‐NO3) were determined experimentally using oxygen bomb calorimetry: ΔcombH(DNB)=5195±200 kJ kg−1, ΔcombH(HDAT‐NO3)=7900±300 kJ kg−1. The standard enthalpies of formation (ΔfH°) of DNB and HDAT‐NO3 were obtained on the basis of quantum chemical computations at the electron‐correlated ab initio MP2 (second order Møller‐Plesset perturbation theory) level of theory using a correlation consistent double‐zeta basis set (cc‐pVTZ): ΔfH°(DNB)=−353 kJ mol−1, −1 829 kJ kg−1; ΔfH°(HDAT‐NO3)=+254 kJ mol−1, +1 558 kJ kg−1. The detonation velocities (D) and detonation pressures (P) of DNB and HDAT‐NO3 were calculated using the empirical equations by Kamlet and Jacobs: D(DNB)=8.66 mm μs−1, P(DNB)=33.9 GPa, D(HDAT‐NO3)=8.77 mm μs−1, P(HDAT‐NO3)=33.3 GPa. 相似文献
7.
Recently, 5‐amino‐1H‐tetrazole is developed for practical use as a substitute for sodium azide, which is conventionally used as a fuel component of gas generating agents for automobile airbags. In this study, the combustion mechanisms of the mixtures 5‐amino‐1H‐tetrazole/potassium nitrate and 5‐amino‐1H‐tetrazole/sodium nitrate have been examined. It has been found that the Granular Diffusion Flame model is applicable to the tested samples even when a molten layer exists at the burning surface. In addition, it is shown that within the pressure range of 1–5 MPa, the greatest factor which affects the burning rate is the diffusion process. It is also demonstrated that the fuel component decomposes first, and the oxidizer decomposes next. Meanwhile, it has also been confirmed that the burning rate increases with an increase in pressure because the flame approaches the burning surface and the amount of heat transfer to the solid phase increases. In spite of a decrease in the amount of heat transfer from the gas phase to the solid phase and an increase in the thickness of the condensed phase reaction zone for a mixture with higher fuel content, there are little differences in the burning rates probably because of an increase in the rate of decomposition of the solid phase. 相似文献
8.
Sanjay V. Ingale Pulya Umamaheswara&#x;Sastry Pratap B. Wagh Arvind K. Tripathi Raghvendra Tewari Vaisyappattu B. Jayakrishnan Suhas B. Phapale Pandugula T. Rao Rajbal D. Wasnik Bikas Bhattacharya Satish C. Gupta 《Propellants, Explosives, Pyrotechnics》2013,38(4):515-519
RDX is preferred as explosive in munitions due to its balance of power and sensitivity that is known to be dependent on its particle size and size distribution. In this study, we prepared nano‐sized RDX in a silica xerogel matrix using a sol‐gel method and investigated its sensitivity for explosive properties. The presence of RDX in composite xerogel was confirmed by TG‐DSC and FTIR techniques. Microstructure and porosity were characterized by transmission electron microscopy (TEM), small angle X‐ray scattering, and N2‐physisorption techniques. TEM results showed that the size of RDX particles in the RDX‐silica composites is in the range of 10–30 nm. The sensitivity to impact and friction was found to be higher for the composites compared to raw RDX. It was also found to be significantly dependent on the acetone/TMOS ratio used in the preparation. 相似文献
9.
Chaza Darwich Thomas&#x;M. Klaptke Jan&#x;M. Welch Muhamed Suceska 《Propellants, Explosives, Pyrotechnics》2007,32(3):235-243
3,4,5‐Triamino‐1,2,4‐triazolium 5‐nitrotetrazolate ( 2 ) was synthesized in high yield from 3,4,5‐triamino‐1,2,4‐triazole (guanazine) ( 1 ) and ammonium 5‐nitrotetrazolate. The new compound 2 was characterized by vibrational (IR and Raman) and multinuclear NMR spectroscopy (1H, 13C, 15N), elemental analysis and single crystal X‐ray diffraction (triclinic, P(‐1), a=0.7194(5), b=0.8215(5), c=0.8668(5) nm, α=75.307(5), β=70.054(5), γ=68.104(5)°, V=0.4421(5) nm3, Z=2, ϱ=1.722 g cm−1, R1=0.0519 [F>4σ(F)], wR2(all data)=0.1154). The 15N NMR spectrum and X‐ray crystal structure (triclinic, P‐1, a=0.5578(5), b=0.6166(5), c=0.7395(5) nm, α=114.485(5)°, β=90.810(5)°, γ=97.846(5)°, V=0.2286(3) nm3, Z=2, ϱ=1.658 g cm−1, R1=0.0460 [F>4σ(F)], wR2(all data)=0.1153) of 1 were also determined. 相似文献
10.
The conductor‐like screening model for real solvents (COSMO‐RS) has previously been shown to give accurate aqueous solubilities for a range of organic compounds using only quantum chemical simulation data. Application of this method for solid organic explosives, however, faces two difficulties; it requires correction for the free energy of fusion (a generally unknown quantity for these compounds) and it shows considerable error for common explosive classes such as nitramines. Herein we introduce a correction factor for COSMO‐RS that is applicable to a wide range of explosives, and requires no data beyond a quantum chemistry calculation. This modification allows COSMO‐RS to be used as a predictive tool for new proposed explosives or for systems lacking experimental data. We use this method to predict the temperature‐dependent solubility of solid explosives in pure and saline water to an average accuracy of approximately 0.25 log units at ambient temperature. Setschenow (salting‐out) coefficients predicted by this method show considerable improvement over previous COSMO‐RS results, but are still slightly overestimated compared to the limited experimental data available. We apply this method to a range of military, homemade, and “green” explosives that lack experimental seawater solubility data, an important property for environmental fate and transport modeling. 相似文献
11.
In the early 1970s PEX were being developed in order to produce energetic compounds with a toothpaste‐like consistency so that the PEX could be moved into position when arming the warhead. In the late 1990s development work was conducted on PEX for the filling of small‐volume microdevices such as microactuators. More recently Cranfield University has just begun research into the development of SPEX. This review outlines the developments in high explosive pastes and concludes with future developments in PEX. 相似文献
12.
Eduardo A. Espinosa‐Fuentes Leonardo C. Pacheco‐Londoo Marcos A. Barreto‐Cabn Samuel P. Hernndez‐Rivera 《Propellants, Explosives, Pyrotechnics》2012,37(4):413-421
A novel method used to synthesize diacetone diperoxide (DADP) from acetone and hydrogen peroxide without the presence of a catalytic agent is presented. Previously reported syntheses used toluenesulfonic and m‐sulfonic acid as catalyst. DADP was prepared with a purity of 99.99 %. The melting point range (128.5–134.5 °C) is consistent with reported values. The success of the reported procedure depends on controlling the ratio between acetone and hydrogen peroxide as well as the temperature of the reaction mixture. The purified crystalline DADP samples were characterized using NMR, Raman, and IR spectroscopy, differential scanning calorimetry, gas chromatography and open atmosphere chemical ionization mass spectrometry (DART™). The structure was compared to the well‐known cyclic trimer triacetone triperoxide (TATP). The proposed synthetic scheme can be useful for preparing small amounts of the cyclic organic peroxide for characterization and fundamental studies and for formulation of gas chromatography, high performance liquid chromatography, and mass spectrometry standards. 相似文献
13.
Davin G. Piercey David E. Chavez Stefanie Heimsch Christin Kirst Thomas M. Klaptke Jrg Stierstorfer 《Propellants, Explosives, Pyrotechnics》2015,40(4):491-497
This study reports the preparation of 1‐amino‐1,2,3‐triazole‐3‐oxide (DPX2) and its transformation to 1,2,3,4‐tetrazine‐1‐oxide. DPX‐2 provides insight into a novel N‐oxide/N‐amino high‐nitrogen system, being the first energetic material in this class. The ability of this material to undergo a nitrene insertion forming 1,2,3,4‐tetrazine‐1‐oxide was also studied, and evidence for this material, the first non‐benzoannulated 1,2,3,4‐tetrazine‐1‐oxide, is presented. The existence of both of these materials opens new strategies in energetic materials design. DPX2 was characterized chemically (Infrared, Raman, NMR, X‐ray) and as a high explosive in terms of energetic performances (detonation velocity, pressure, etc.) and sensitivities (impact, friction, electrostatic). DPX‐2 was found to possess good thermal stability and moderate sensitivities, indicating the viability of N‐amino N‐oxides as a strategy for the preparation of new energetic materials. 相似文献
14.
David E. Chavez Damon Parrish Daniel N. Preston Isaac W. Mares 《Propellants, Explosives, Pyrotechnics》2012,37(6):647-652
This paper describes the synthesis and characterization of several salts of 4,4′,5,5′‐tetranitro‐2,2′‐biimidazolate (N4BIM). Each of the salts were characterized chemically, thermally, morphologically, as well as with respect to destructive stimuli (impact, electrostatic discharge, friction, thermal). These salts show promise as propellant ingredient additives, and in particular, the bis‐triaminoguanidinium salt of N4BIM displays excellent burn rate and combustion behavior. Our combustion studies have shown that TAGN4BIM displays a fast burning rate and has the lowest pressure dependence exponent yet measured for a triaminoguanidinium salt. 相似文献
15.
Jason J. Phillips 《Propellants, Explosives, Pyrotechnics》2012,37(2):223-229
This investigation is to improve the Type‐12 impact sensitivity test apparatus through the merging of basic split‐Hopkinson pressure bar principles with existing impact sensitivity testing methods. This is accomplished mainly through the addition of resistance strain gage equipment. Upon completion of the modifications to the apparatus, incident pressure waves created by impact are recorded, as well as sharp pressure releases suspected to be caused by rapid mechanical failure of energetic material samples. To solve data acquisition issues during the initial testing attempts with the modified equipment, the Type‐12 tooling is further adapted by installing a high‐density polyethylene (HDPE) bushing through which the striker bar is inserted. A series of sensitivity tests are then conducted using RDX to determine if this alteration affected the normal operation of the instrument. It is found that this modification to the apparatus creates a 46 % reduction in the standard deviation of H50 results in comparison to the standard tooling. 相似文献
16.
Waldemar&#x;A. Trzci&#x;ski Stanis&#x;aw Cudzi&#x;o Jzef Paszula James Callaway 《Propellants, Explosives, Pyrotechnics》2008,33(3):227-235
Detonation performance of non‐ideal RDX‐based compositions was studied. Charges of phlegmatised RDX containing 30% of two types of aluminium powders, coarse aluminium oxide or fine lithium fluoride particles were tested. The research concerning influence of inert and reactive additives on the detonation velocity and quasi‐static pressure was carried out. To estimate the degree of afterburning of the detonation products and reactive particles, closed explosions were performed in a chamber filled with different atmospheres. Explosion residues were also analysed. Gasdynamical and thermochemical calculations were also performed for the tested explosive compositions. 相似文献
17.
Chaoyang Zhang Qiang Peng Liyan Wang Xiaochuan Wang 《Propellants, Explosives, Pyrotechnics》2010,35(6):561-566
The Five‐Second Explosion Point (5‐SEP) tests and the SEM detections in this research showed that the HMX crystals and the HMX‐based explosives treated under different conditions can possess different thermal sensitivities. That is to say, higher impurity, smaller granularity, and worse integrity of HMX crystals can make them more thermally sensitive. The addition of metal or metal oxide particles, especially nanoparticles to HMX can also enhance its thermal sensitivity. Meanwhile, coating of HMX crystals with polymers to form perfect PBX and to keep them undamaged are helpful to decrease their thermal sensitivity. Furthermore, the thermal sensitivity of temperature‐aged HMX changes differently in terms of the integrity of its particles. Therefore, it can be concluded that conditions which increase the surface energy of HMX crystals or which make the HMX molecules more active to decompose at lower temperature will increase the thermal sensitivity of HMX. Additionally, the variation in the thermal sensitivity of HMX treated under different conditions is generally more temperate than that of its mechanical sensitivity. 相似文献
18.
David&#x;E. Chavez Bryce&#x;C. Tappan Benjamin&#x;Aaron Mason Damon Parrish 《Propellants, Explosives, Pyrotechnics》2009,34(6):475-479
This paper describes the synthesis and characterization of bis‐(triaminoguanidinium)‐3,3′‐dinitro‐5,5′‐azo‐1,2,4‐triazolate (TAGDNAT), a novel high‐nitrogen molecule that derives its energy release from both a high heat of formation and intramolecular oxidation reactions. TAGDNAT shows promise as a propellant or explosive ingredient not only due to its high nitrogen content (66.35 wt.‐%) but also due to its high hydrogen content (4.34 wt.‐%). This new molecule has been characterized with respect to its morphology, sensitivity properties, explosive, and combustion performance. The heat of formation of TAGDNAT was also experimentally determined. The results of these studies show that TAGDNAT has one of the fastest low‐pressure burning rates (at 6.9 MPa) measured till date, 6.79 cm s−1 at 6.9 MPa (39% faster than triaminoguanidinium azotetrazolate (TAGzT), a comparable high‐nitrogen/high‐hydrogen material). Furthermore, its pressure sensitivity is 0.507, a 33% reduction compared to TAGzT. 相似文献
19.
Thomas&#x;M. Klaptke Burkhard Krumm F.&#x;Xaver Steemann 《Propellants, Explosives, Pyrotechnics》2009,34(1):13-23
1,3‐Diazido‐2‐nitro‐2‐azapropane (DANP) and 1,7‐diazido‐2,4,6‐trinitro‐2,4,6‐triazaheptane (DATH) were synthesized, thoroughly analyzed, and their explosive properties and sensitivities toward friction and impact were measured. The precursors 1,3‐diacetoxy‐2‐nitro‐2‐azapropane ( 1 ), 1,3‐dichloro‐2‐nitro‐2‐azapropane ( 3 ), and 1,7‐dichloro‐2,4,6‐trinitro‐2,4,6‐triazaheptane ( 4 ) – as well as DATH – were furthermore characterized by X‐ray diffraction. 相似文献
20.
Elizabeth G. Francois David E. Chavez Mary M. Sandstrom 《Propellants, Explosives, Pyrotechnics》2010,35(6):529-534
Process optimization studies were performed for the preparation of the high explosive 3,3′‐diamino‐4,4′‐azoxyfurazan (DAAF). These process studies were pursued to address issues such as problematic waste generation products, particle size, impurities, and manufacturability. This paper describes the original synthesis method and inherent issues. An optimization process was designed to investigate the issues with purity and manufacturability. Particle size effects were addressed by adding a recrystallization step to the synthesis. Ultimately, a complete solution to all observed issues was found with a new synthesis process, which now allows DAAF to be prepared without any impurities, with good particle size and without the need for recrystallization. Importantly, the new synthesis process can be performed in an environmentally friendly manner, with the production of non‐hazardous waste. 相似文献