Showing papers in "Journal of Energetic Materials in 1985"
TL;DR: In this paper, a simple empirical equation D = aQ½ + bw ∫0, a = 67.6, b = 243.2; adiabat exponent by a equation Γ = r + Γ0 (1 − e−0.5461).
Abstract: Detonation velocity of explosives including single compounds and mixtures may be calculated by means of a simple empirical equation D = aQ½ + bw ∫0, a = 67.6, b = 243.2; adiabat exponent by a equation Γ = r + Γ0 (1 − e−0.5461.). Thus, the detonation pressure can be estimated from the theoretical equation P = ∫0D2/(1 + Γ). Q is the heat of detonation, w is the potential energy. Γ is the adiabat exponent, and ∫0 is the initial density. The agreements between the calculated results and the experimental data are reasonably satisfactory.
37 citations
TL;DR: In this paper, the decomposition of CH3NO2 in a shock tube has been studied by using a frequency-stabilized CW CO laser to measure the real-time production of NO and CO, two of the key decompositio...
Abstract: The decomposition of nitromethane (CH3NO2) in a shock tube has been studied by using a frequency-stabilized CW CO laser to measure the real-time production of NO and CO, two of the key decompositio...
35 citations
TL;DR: In this article, a radical mechanism was proposed and computer-modelled to account for the disappearance of DMNA and the production of (CH3)2NNO and CH3NO2.
Abstract: Dimethylnitramine (DMNA) was pyrolyzed between 466 and 524 K at about 475 Torr pure DMNA pressure in static cells. A radical mechanism was proposed and computer-modeled to account for the disappearance of DMNA and the production of (CH3)2NNO and CH3NO2. The rate constant for DMNA decomposition into (CH3)2N and NO2, based on these low-temperature results and other high-temperature shock tube data, covering 460–960 K, can be given by k1 = 1015.9±0.2 exp(−22,000±200/T) sec−1. This result leads to values for the N-N bond energy of 43.3±0.5 kcal/mole and the heat of formation of the (CH3)2N radical, 35±2 kcal/mole at 298 K. Kinetic modeling of the CH3NO2 and (CH3)2NNO production profiles has been carried out.
26 citations
TL;DR: In this paper, gas chromatography was employed to analyze RDX residues recovered from impact tests involving a 5 kg mass dropped from 10, 12, and 14 cm heights, and two nitroso compounds were detected at levels of (0·80 to 9·3) × 10−10 percent and (1·3 to 560) ×10−10 percentage, respectively.
Abstract: Quantitative results are presented for the formation of two nitroso compounds during the drop-weight impact of Holston production-grade Class D RDX explosive crystals. Gas chromatography, using a sensitive Ni-63 electron capture detector, was employed to analyze “RDX residues” recovered from impact tests involving a 5 kg mass dropped from 10, 12, and 14 cm heights. The compounds, 1,3,5-trinitroso-1,3,5-triazacyclohexane (R) and 1,3-dinitroso-5-nitro-1,3,5-triazacyclohexane (RO) were detected at levels of (0·80 to 9·3) × 10−10 percent and (1·3 to 560) × 10−10 percent, respectively. More RO than R was formed at the 14 cm drop height. This appears to be the first time that nitroso compounds structurally similar to RDX have been observed in impacted RDX crystals.
18 citations
TL;DR: In this paper, the reactive hydrodynamics of desensitization of heterogeneous explosives by shocks too weak to initiate propagating detonation in the geometries studied were investigated.
Abstract: The reactive three-dimensional hydrodynamic Code 3DE has been used to investigate the reactive hydrodynamics of desensitization of heterogeneous explosives by shocks too weak to initiate propagating detonation in the geometries studied. The preshock desensitizes the heterogeneous explosive by closing the voids and making it more homogeneous. A higher pressure second shock has a lower temperature in the multiple shocked explosive than in single shocked explosive. The multiple shock temperature may be low enough to cause a detonation wave to fail to propagate through the preshocked explosive.
6 citations
TL;DR: In this article, the assignment of certain ESR signals from thermally decomposed RDX and HMX to a nitroxyl radical (RNO·) has been discussed.
Abstract: The thermal decomposition of RDX produces free radical intermediates which are detected by using ESR (electron spin resonance) spectroscopy. The assignment of certain ESR signals from thermally decomposed RDX and HMX to a nitroxyl radical (RNO·) has been discussed in earlier publications. Spectral data from isotopically labelled RDX (RDX-d6 and RDX-15NO2) supports a nitronylnitroxyl radical (R(N+−O−)NO·) assignment to the ESR signals detected during liquefaction of RDX at 200°C.
6 citations
TL;DR: It was found that the relationships were not applicable to all explosives, in particular, insensitive high explosives and propellants did not conform to the empirical equations.
Abstract: Recent data collected from the literature were used to test the general applicability of proposed empirical correlations of sensitivity data of high explosives (HE) and propellants. It was found that the relationships were not applicable to all explosives. In particular, insensitive high explosives and propellants did not conform to the empirical equations.
4 citations
TL;DR: In this article, the reaction of TATB in aqueous, strongly basic solutions gave metal salts of 1,3,5-trihydroxy-2,4,6-trinitrobenzene (THTNB) also called trinitrophloroglucinol.
Abstract: Reactions of TATB in aqueous, strongly basic solutions gave metal salts of 1,3,5-trihydroxy-2,4,6-trinitrobenzene (THTNB) also called trinitrophloroglucinol. Thus, we prepared potassium, sodium, and barium salts. The mono- and diammonium salts were prepared by treating THTNB with ammonia and ammonium hydroxide, respectively. Some explosive properties of the salts were evaluated. From the physical characteristics of the salts in various solvents, a spot test was developed for known high explosives (HE) containing TATB.
4 citations
TL;DR: In this paper, a simplified procedure for preparing cellulose nitrate containing less than 10% nitrogen is described, and extensive chain degradation also occurred, increasing with the nitrogen content of the CN used, and with the alkalinity of the reagent.
Abstract: Replacement of the nitrate groups in cellulose nitrate (CN) to varying degrees by azide, bromide, iodide, thiocyanate, or nitro groups was accomplished by heating with the corresponding alkali-metal salt in organic solvents. Extensive chain degradation also occurred, increasing with the nitrogen content of the CN used, and with the alkalinity of the reagent; this was the sole reaction with sodium cyanide. A simplified procedure for preparing CN containing less than 10% nitrogen is described.
4 citations
TL;DR: In this paper, the authors used the observation that the jet initiation of covered and bare explosive occurs by quite different mechanisms to devise a novel technique for producing either prompt detonation at a predetermined position within an explosive charge or failure and disruption.
Abstract: The observation that the jet initiation of covered and bare explosive occurs by quite different mechanisms has been used to devise a novel technique for producing either prompt detonation at a predetermined position within an explosive charge or failure and disruption. The method consists of firing a jet at an appropriately covered explosive containing a void located where the onset of detonation is required. The void contains a low density medium to dissipate the bow wave shock and may be positioned within the bulk of the explosive or on the surface. When the jet strikes the far side of the void prompt detonation occurs and spreads throughout the explosive. However, when the jet is aimed to miss the void, failure occurs. The technique is described in detail and illustrated by flash radiographs showing both the detonation and failure modes for a Composition B charge containing a spherical void located near its center. For Composition B the estimated maximum depth of locating the void, and therefo...
4 citations
TL;DR: In this article, the chemical shift anisotropy of ammonium nitrate was measured by two different methods at room temperature, and a precise measurement of the difference in isotropic chemical shift occurring at the phase transition IV to III was reported.
Abstract: Exploratory Nitrogen-15 nuclear magnetic resonance (NMR) studies of ammonium nitrate (AN) have been undertaken using both conventional and magic angle spinning (MAS) methods. The chemical shift anisotropy is measured by two different methods at room temperature, and a precise measurement of the difference in isotropic chemical shift occurring at the phase transition IV to III is reported. Finally, the activation energy for the motion of both ions in the room temperature phase are obtained. No evidence in discontinuity of nitrogen relaxation times across the phase boundary at 32°C was observed.
TL;DR: In this article, the phase diagram was determined for the ternary system diethylenetriamine trinitrate/ethylenediamine dinitrates/ammonium nitrate with 15 wt% potassium nitrate (DETN/EDD/AK15).
Abstract: The phase diagram was determined for the ternary system diethylenetriamine trinitrate/ethylenediamine dinitrate/ammonium nitrate with 15 wt% potassium nitrate (DETN/EDD/AK15). The eutectic mixture (DEAK), containing 40, 35, and 25 wt% AK15, DETN, and EDD respectively, was subjected to small-scale sensitivity and performance tests. The measured PCJ (223 kbar) from a 4.13-cm-diam, unconfined rate-stick test of the DEAK system agrees with Kamlet-Short-Method (KSM) data calculated at the same pressed density [97.7% of theoretical maximum density (TMD)]. A rate-stick test of EAK at the same charge diameter and pressed density failed, indicating that the addition of the DETN component to the EAK system has reduced the critical diameter of EAK.
TL;DR: In this article, the burning and ignition properties of Composition (Comp) B are studied so that formulation modification could be made that would reduce gun projectile in-bore thermal explosions.
Abstract: The burning and ignition properties of Composition (Comp) B are studied so that formulation modification could be made that would reduce gun projectile in-bore thermal explosions. Comp B first burns on its surface like a gun propellant; then, at a pressure near 100 MPa, a sudden breakup burning phase develops. New surface area is created at a phenomenal rate, and this is the cause of the catastrophic reaction rates that it can experience. Coating its RDX constituent with a protectant significantly slows this reaction rate. It appears to do this by inhibiting the rate at which the RDX is released from the TNT matrix for burning, probably by infinitesimally delaying the ignition of the RDX in the particle ignition sequence. A new test that evaluates explosive ignitability as a function of pressure and energy indicates that an RDX protective coating may also increase the level of thermal ignition and delay the onset of a thermal explosion. Collectively, these three desirable properties, caused by a ...
TL;DR: In this paper, a spectrophotometric procedure to determine the purity of barium styphnate monohydrate based on the absorbance of the staphnate ion at 326 and 413 nm has been developed.
Abstract: A spectrophotometric procedure to determine the purity of barium styphnate monohydrate based upon the absorbance of the styphnate ion at 326 and 413 nm has been developed. The purity is determined by comparing the absorbance of the styphnate ion in barium styphnate and styphnic acid at pH 6.8. Our investigation has shown that the molar absorptivities and maxima of the aqueous solution of styphnic acid are quite pH dependent; therefore, the pH is buffered to 6.8–7.0 with ammonium acetate. Under these conditions the molar absorptivity is (1.63±0.03)×104 1/mole cm. Analyses following the procedure in the Navy specification WS13444A using water were found to give low molar absorptivities (1.3×104 1/mole cm) for the styphnic acid calibration resulting in erroneous values for barium styphnate purity.
TL;DR: In this article, the performance of model CC primers based on production M5 2 DEFA and M52A3B1 primers are compared and the relationship between the carbon black content and experimental parameters resistance, resistance spread, energy sensitivity and functioning times are determined.
Abstract: Performance of model CC primers based on production M5 2 DEFA and M52A3B1 primers are compared. The relationships between the carbon black content and experimental parameters resistance, resistance spread, energy sensitivity and functioning times are determined. Although both types of primer have comparable energy sensitivity at equal carbon black content, resistances are much higher and functioning times longer for the M52A3B1 type. It is suggested that the longer functioning times result from a slower buildup to fast burning following ignition. The consequences of this for developing a CC primer with low energy sensitivity are outlined.
TL;DR: In this paper, computer molecular dynamics has been used to study the shock-front transition region for a series of two-dimensional hydrogen-bonded structures composed of water-vapor molecules.
Abstract: Computer molecular dynamics has been used to study the shock-front transition region for a series of two-dimensional hydrogen-bonded structures composed of water-vapor molecules. Two different structures were examined and different intermolecular potentials were considered. Sample sizes and running times were chosen to correspond to the predicted shock-front rise-time in real water. In this way, the effect of different potentials and initial structures on the equilibration associated with the shock-front transition in water could be investigated. In addition to studying the development and incipient relaxation of shock-polarization states, we have also considered the propagation and possible incipient relaxation of structural phase transitions occurring in two-dimensional structures. The results of these molecular dynamics calculations are compared with the experimental shock behavior of real water; in particular, comparisons are made with respect to intermolecular hydrogen-bond breaking, dissoci...
TL;DR: In this article, the synthesis of difunctional dinitronitramino compounds, where either R or R' or both contain a hydroxyl group, is described, and the compounds include hydroxyesters, hydroxyacids and diols.
Abstract: The synthesis of difunctional dinitronitramino compounds, R-C(NO2)2CH2N(NO2)-R', where either R or R' or both contain a hydroxyl group, is described. The compounds include hydroxyesters, hydroxyacids and diols. Energetic polyesters were prepared from the hydroxyacids.