bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polymers with High‐Energy Substituents: Polyesters containing azidomethyl groups
Authors: Keicher Thomas , Wasmann Friedrich‐Wilhelm 
Published: May 2005

AbstractThis paper describes the synthesis of linear azidopolyesters which appear suitable as high‐energy binders in explosive systems. Preparation is carried out via a nucleophilic substitution reaction from the corresponding halogenic polyesters with sodium azide. In the polycondensation of the halogen derivates, the authors examined the influence of the intial compound ratio of dicarbonic acid and diol on the distribution of end groups and molecular weight. In this work it was found that the azido group could be introduced into the polyester backbone relatively easily. Some properties of polyesters are fundamentally changed through the introduction of the azido group. The changes as regards viscosity, thermal stability and glass transition temperature were documented and the friction and impact sensitivities recorded.
Optimization of Liquid Gun Propellants based on nitromethane/methanol by physical and chemical modifiers
Authors: Langer Gesa , Schmid Helmut , Koppenhöfer Wolfgang 
Published: May 2005

AbstractMain topics of developing and optimizing liquid gun propellants are the suppression of oscillations, and increase in performance and an improvement of electrical conductivity. Additives for the liquid system nitromethane/methanol will be described, that will change the evaporation and reaction kinetics by varying the physical and chemical properties. This will lead to an improved escillation behavior.Energetic additives, based on organic azido‐compounds, will cause a significant enhancement in performance. The electrical conductivity is improved by special compounds on the base of transition metal nitrates.The investigations show a small effect of the physical modifiers. A significant suppression of oscillations is reached by mechnistical additives. Using these additives, the interaction of the specific energy with an accompanying increase in intensity of oscillation ‐ will be minimized. As a consequence, the possibility of an additional enhancement in performance is given, due to the developed energetic additives.
Dynamic Behavior of Composites under Preloading
Authors: Geißler Adam , Geißler Egon 
Published: May 2005

AbstractPolymers with characteristic damping properties are obtained by compounding them with additives. The mechanical behavior under vibration conditions of these compounds is characterized by dynamic moduli which depend on the static preload. The test results of a PU‐compound are presented in this paper. The obtained results enable one to calculate the complex moduli of a special dynamic constitutive equation, which then enables one to calcualte stress and strain of dynamic deformations of structures under static preload. The paper presents a method to calculate such loading conditions on a system, too. A finite element analysis is used to determine the frequency response which characterizes the damping behavior of the structure.
Synthesis of N‐2,4,6‐trinitrophenyl‐N'‐2,4‐dinitrobenzofuroxano‐3,5‐dinitro‐2,6‐diaminopyridine
Authors: Naixing Wang , Boren Chen , Yuxiang Ou 
Published: May 2005

AbstractN‐2,4,6‐trinitrophenyl‐N' ‐2,4‐dinitrobenzofuroxano‐3,5‐dinitro2,6‐diaminopyridine has been synthesied from 2,6‐diaminopyridine and dinitrodichlorobenzene as well as 2,4,6‐trinitrochlorobenzene. For this compound, the structure has been determined by elemental analysis, IR 1HNMR, and MS spectroscopies.
Polymer Binder for High Performance Explosives
Authors: Akhavan J. , Burke T. C. 
Published: May 2005

AbstractAn evaluation on coating HMX crystals with three different polymeric binders using the “solvent slurry process” was conducted. Three polymers employed were:

a thermoplastic copolymer [Kel‐F 3700],
a thermoplastic elastomer [kraton‐G 1650] and
a polyurethane [Impranil DLH].

Kel‐F 3700 presented an electrostatic hazard and was too insoluble for application by the slurry process. Kraton‐G 1650 presented a similar electrostatic hazard and its process yield was low. Impranil DLH produced a high yield using the batch slurry process.
Study of the Blast Wave Parameters from Small Scale Explosions
Authors: Ismail M. M. , Murray S. G. 
Published: May 2005

AbstractAlthough the science of blast overpressure is well understood there are major difficulties in obtaining accurate values for peak overpressure, positive duration, and positive impulse. These parameters are required to assess damage potential of blast overpressures. This paper describes the problems associated with such measurements and how the problems can be overcome by the use of known analytical techniques based on the modified Friedlander equation. Other methods used include curve smoothing of the pressure‐time history and integration to obtain impulse values through which the curve decay parameter can be found. Several different analytical methods are compared.The experiments have been carried out on small charges (200 g and 400 g) and the results obtained analysed to assess far‐field distances for such charges. This has been achieved by comparing peak overpressure values with the scaled distance.
On the Use of AMl and PM3 Methods on Energetic Compounds
Authors: De Paz Jose‐Luis G. , Ciller Juan 
Published: May 2005

AbstractStewart's new semi‐empirical method MNDO‐PM3 (PM3) is compared with the well known Dewar's AMl method in the study of nitrosubstituted compounds, and some energetic materials. PM3 method shows better performances than the AMl one. Adjacent lone pair/lone pair repulsion are better described at PM3 level and the known systematic correction of about −9 kcal/mol for each C‐NO2 group of the AMl method becomes +3.5 kcal/mol at PM3 level. PM3 results for N‐NO2 containing compounds are directly comparable with experimental gas phase data.
“Tris‐X”(1), A New High Energy Polynitramine Explosive: Synthesis using dinitrogen pentoxide (n2O5) technology(2), characterization, and thermal stability and hazard assessment
Authors: Millar R. W. , Paul N. C. , Richards D. H. , Bunyan P. , Golding P. , Rowley J. A. 
Published: May 2005

AbstractThis paper describes the synthesis and characterization of two novel heterocyclic trinitramines from readily available starting materials, as well as the evaluation of one of them (“Tris‐X”) as a high explosive. The syntheses, which utilize the ability of dinitrogen pentoxide (N2O5) to cleave aziridine rings to yield vicinal nitramine‐nitrates, proceed in high yield to give crystalline products with melting point below 100°C. The characterization of the products by IR, NMR (1H and 13C), mass spectrometry and elemental analysis is described, and whilst possessing high explosive power (the Pcj for Tris‐X is calculated at ca 300 kbar) they were found to exhibit acceptable hazard properties (impact sensitivity, temperature of ignition etc). The thermal stability measurements (by DSC and chemiluminescence) however indicated only marginally acceptable stability.
Correlation of physical and chemical properties of c‐h‐n‐o explosives (part II)
Authors: Lee Jaimin , Block‐Bolten Andrew 
Published: May 2005

AbstractIn our previous paper(1) we correlated the physical, chemical, and thermodynamic properties of C‐H‐N‐O explosives with their constant‐volume explosion properties calculated by using the Taylor model implemented in the Nitrodyne code. In this paper, we added the correlations for the Chapman‐Jouguet detonation properties calculated by using the Becker‐Kistiakowsky‐Wilson equation of state implemented in the TIGER code. By splitting the correlation variable (F) used in Reference 1 into a density term and a density‐independent term (f), Chapman‐Jouguet detonation pressure and velocity showed simple linear relationships with square root of the new correlation variable (f). Other detonation properties were derived from the detonation pressure and velocity: Correlation of constant‐volume explosion properties with the new correlation variable (f) showed both a moderate improvement, compared to those with the old correlation variable (F), and a much simpler relationship.
Thermal Decomposition of AMMO/AP Composite Propellants
Authors: Oyumi Yoshio , Mitarai Yoshiaki , Bazaki Hakobu 
Published: May 2005

AbstractThermal decomposition of AMMO/AP composite propellants was studied by DTA, TGA and DSC in helium atmosphere. The effects of accelerated aging at 347 K for 370 days on decomposition kinetics were also measured. AMMO/AP propellant showed two different decomposition steps, which were mainly the AMMO binder decomposed region and the reaction of AP dominated region. These regions were separated at around 20 % weight loss point at the condition used in this study. AMMO binder decomposition and AP decomposition were strongly related each other. The heat generated by the AMMO binder decomposition initiated and accelerated the thermal decomposition of AP. Although both Fe2O3 and CFe activated the thermal decomposition of AMMO/AP propellants, CFe mainly accelerated the decomposition of AMMO binder and Fe2O3 catalyzed the AP reactions which consisted of the AP decomposition and the reaction between decomposed AP and decomposed AMMO binder. AMMO/AP composite propellants were thermally stable even after aging at 347 K for 370 days.
Numerical Simulation of Penetration by explosively‐formed projectiles
Authors: Zukas J. A. , Weickert C. A. , Gallagher P. J. 
Published: May 2005

AbstractNumerical solution techniques have advanced to the point where calculations of explosively‐formed penetrator formation and penetration can be performed as a matter of routine on current wave propagation computer codes, popularly known as hydrocodes. Results, however, depend to a very large extent on the experience of the code user and familiarity with the capabilities and eccentricities of the particular code used for simulations. In this paper we look at the effects of spatial resolution and material strength on the simulation of penetration of thick mild steel plates by an explosively‐formed penetrator of Armco iron. For good correlation with experiments, careful attention must be paid to the details of the computational grid. Likewise, material data must be determined from experiments appropriate for the range of strain rates encountered in the impact event.
Impact Initiated Annular Retonation Wave in explosive
Authors: Chou Pei Chi , Roslund Leslie , Liang Deshou 
Published: May 2005

AbstractExperiments conducted at the White Oak Laboratory with a pentolite explosive charge impacted by a flat‐ended cylinder of mild steel, showed a hole drilled at the center of the impactor, if the explosive was detonated. A computer simulation was carried out with the finite element hydrocode DEFEL and the Forest‐Fire reaction‐rate model. Computed results verified the hypothesis that the annular retonation was the cause of the drilled hole. The detonation started at a distance of about 10 mm from the impact surface, then developed into an annular shape and propagated inwards and backwards, to the axis of symmetry and the impact surface. The converging wave generated a pressure of about 100 GPa near the center of its impact surface, which is believed to be the real cause of the hole.
Dynamic Behavior of a Shear‐Formed Shaped‐Charge Liner
Authors: Wiener K. , Shaw L. , Muelder S. , Breithaupt D. , Baum D. 
Published: May 2005

AbstractA high‐resolution, multi‐frame, image‐converter camera developed for high speed photography is applied to study the dynamic behavior of shear‐formed shaped‐charge liners. Grid lines applied to the inner liner surface allow the precise quantification of liner collapse, early jet formation, and jet development for comparison with two‐dimensional hydrocode simulations. The technique affords the first direct measurement of the angular velocity of jets formed from shear‐formed shaped‐charge liners.
On the Nature of Boron Nitride E‐Phase
Authors: Batsanov S. S. , Kopaneva L. J. , Lazareva E. V. , Kulikova I. M. , Barinsky R. L. 
Published: May 2005

AbstractA review of the works, in which the E‐phase of boron nitride had been obtained under various physical treatments, revealed that in all cases during the formation or isolation of the E‐phase the sample can be impurified with oxygen. An X‐ray spectral study of crystalline E‐phase obtained in the present work proved it to be a solid solution of the type BN1 − xOx containing B‐B bonds.
Processing of Trinitrotoluene‐Water Emulsions
Authors: Teipel Ulrich 
Published: May 2005

AbstractWhen disposing of trinitrotoluene (TNT), the TNT‐melt must be pre‐treated. One possibility is to emulsify the melt in water after the TNT has been dismantled from the explosive charge. Production of these emulsions can be accomplished using emulsifying machines based on the rotor‐stator principle, e.g., ring gear dispersing machines or colloid mills. Droplet size reduction results from the normal and tangential stresses applied to the droplet as it is subjected to laminar or turbulent flow fields.Knowledge of the droplet size and droplet size distribution of the dispersed phase is important to determine the quality of an emulsion and the emulsification process. In this paper, results from the discontinuous production of TNT‐water emulsions are presented. In addition, the use of laser diffraction spectrometry for analyzing TNT droplet size is described.
Decomposition of Composite Explosives Containing Ammonium Nitrate by transient adiabatic gas compression
Authors: van Niekerk Albert P. , Brower Kay R. 
Published: May 2005

AbstractThe decomposition products of emulsion explosives and of other composite explosives containing ammonium nitrate, such as ANFO, were investigated. The compounds were thermolyzed at high temperature and pressure on the microsecond and millisecond time scales by adiabatic gas compression. It was found that the first step in emulsion decomposition is pyrolysis of the oil to form reactive intermediates like Hċ and CH3ċ. These reactive species are oxidized by the decomposition products of ammonium nitrate in a later sequence of reaction steps.
Gun Propulsion Concepts. Part I: Fundamentals
Authors: Klingenberg G. , Knöchel H. , Maag H.‐J. 
Published: May 2005

AbstractModern gun propulsion techniques are driven by the desire to increase muzzle kinetic energy as a means to enhance weapon lethality, reduce costs, increase reliability, and improve vulnerability. In recent years, a significant part of research and developmental activities has been focused not only on conventional solid‐propellant and novel liquid‐propellant gun propulsion techniques but also on advanced concepts, particularly those offering substantial performance increase. High performance can be achieved by pure electric systems(coil or rail gun) as well as by combining chemical propulsion either with gasdynamic principles (light gas gun or ram accelerator) or with electrothermal techniques (hybrid gun). Part I of this paper deals with the fundamentals of projectile acceleration techniques. The objective is to provide the basis for understanding gun technology and to lay the basis for assessing present and future developments.
The effect of elastomeric liners on high‐pressure liquid propellant combustion oscillations
Authors: Vosen S. R. , Carling R. W. , Rychnovsky R. E. , Griffiths S. K. , Renzi R. F. 
Published: May 2005

AbstractLiquid propellants are currently being investigated as an alternative to solid propellants in advanced gun designs. The use of liquids may provide advantages in the areas of safety, cost and performance. One area of concern in liquid propellant gun designs is the presence of large pressure oscillations: oscillations of ± 50% of the baseline pressure have been observed. These oscillations may result in a degradation of performance and reliability. The source of pressure oscillations and possible mitigation schemes are being studied in the Sandia Liquid Propellant Injector/Combustor. In this research device, the effect of acoustic liners on pressure oscillations in a high‐pressure (128 MPa) liquid propellant spray combustor is studied for a hydroxylammonium nitrate‐based propellant. In this study we investigated the effects of orientation and coverage fraction of elastomer liners on pressure oscillation reduction. Results for a range of elastomer/steel liner combinations are presented. along with an acoustic model and a correlation the data. The results indicate that: (1) linears can reduce oscillations by approximately three order of magnitude,(2) the reduction in pressure oscillation is independent of the placement of liners relative to the propellant flow, and (3) the magnitude of the oscillations can be correlated with the acoustic properties of the wall material.
Investigation on interfacial bonding in HMX‐containing model propellant composite
Authors: Weishang Yao , Wenhui Wu , Zhanning Jia , Jianwu Dai , Huiming Tan 
Published: May 2005

AbstractA series of novel bonding agents which comprise the structural features of hydantoin and isocyanurate derivatives have been developed. The mechanical properties of model propellant composite containing these novel bonding agents were determined. Wilhelmy plate and wicking methods were used to evaluate wetting properties of these new bonding agents, and the wetting properties were discussed in the respect of thermodynamics and dynamics. Combined with the results obtained from FTIR and XPS analysis, the interfacial bonding of these novel bonding agents with HMX was evaluated.
Detonation Studies with a Ballistic Range Camera
Authors: Held Manfred 
Published: May 2005

AbstractWith an appropriate test setup, the Hadland Photonics Ballistic Range Camera (SVR), designed primarily for exterior and terminal ballistics, can also be used very well for studying initiation events and analysing a variety of detonation phenomena. This paper discusses detonics experiments carried out with the Ballistic Range Camera explaining in detail the test setup and the analysis of the results. The ability of the camera system to superimpose up to 16 images on a single frame allowed particularly detailed examination of detonation propagation, velocity, corner turning distance and the non‐reacting radial zones.
Barrier‐Test
Authors: Held Manfred 
Published: May 2005

AbstractThis paper will explain a test configuration for the diagnostic of the shock wave attenuation of homogeneous and sandwiched inert materials, which measures the delay time between the detonation of a donor and an acceptor charge, as well as the detonation profile in the acceptor charge. Applying the double‐flash‐gap technique, the analyzed pressure levels render possible conclusions about the existence of divergent or convergent detonation waves.
Estimation of ammonium perchlorate in HTPB based composite solid propellants using Kjeldahl method
Authors: Ajaz A. G. 
Published: May 2005

AbstractKjeldahl method has been applied to determine the percentage of ammonium perchlorate (AP) in hydroxy‐terminated polybutadiene (HTPB) based composite solid propellants. It has been found that in pastes containing aluminium (Al) it is important to eliminate all the Al before starting the actual reaction (distillation). The results obtained are in the range of ±0.05% for pastes with and without Al whereas the range is ±0.02% for pure AP. End points are confirmed using pH meter.
Comparative brisant characteristics of some classes of industrial emulsion explosives
Authors: Odintsov Victor V. , Pepekin Vitaly I. 
Published: May 2005

AbstractThe four types of mixtures consisting of the two bases (aqueous solutions of ammonium nitrate and ammonium dinitroamide) and the two additions (hollow glass microballoons and gunpowder) are considered in this work. On the base of thermodynamic computations of an ideal detonation and accompanying processes (shock and rarefaction waves) there were obtained not only the dependences of detonation parameters on addition quantities to mixtures, but the pressure versus particle velocity diagrams, too, which in comparison with Hugoniots relatively soft (water) and hard (aluminium) substances allowed to determine values of pressure in the shock waves being produced in surroundings nearby the end‐wall and lateral surface of a charge. It is proposed to characterize the brisant effect of an explosive by a value of relative brisance which is calculated as percentage ratio of pressures of shock waves generated in surroundings under the same conditions by detonation products of the given explosive and the standard one. It is shown that the brisant effect of the new emulsion explosives is comparable and even can exceed that of TNT of maximal density. It is shown as well that the brisant ability of industrial emulsion explosives can be raised by 60 and more percents by replacing ammonium nitrate with ammonium dinitroamide and hollow glass microballoons with powders being obtained as a result of military industry conversion and utilization of munitions.
Radiation curing of AP/HTPB‐based energetic composites. I. Effect on physico‐mechanical properties
Authors: Dedgaonkar V. G. , Navle P. B. , Shrotri P. G. 
Published: May 2005

AbstractThe use of gamma radiation has been successfully demonstrated as a powerful tool for curing of formulations of ammonium perchlorate and hydroxy‐terminated polybutadiene. This is not possible by conventional methods. The porosity observed in the composite is attributed to the shrinkage of matrix localized around surface of AP particles which creates voids in the bulk. Occurence of shrinkage is in the interphase zone and is due to excessive crosslinking of polybutadiene caused by radiolytic products of AP. Incorporation of toluene diisocyanate and ferric acetyl acetonate showed loss of radiation induced porosity and increase in density, tensile strength and elongation.
The Diffusion of Deterrents into Propellants Observed by FTIR microspectroscopy — Quantification of the diffusion process
Authors: Vogelsanger Beat , Ossola Bruno , Brönnimann Ernst 
Published: May 2005

AbstractThe interior ballistic performance of propellants can be significantly improved by the application of deterrents. However the diffusion of the deterrents from the surface into the propellant grains during long‐time storage may significantly reduce the propellants shelf life.The diffusion of different types of deterrents into single‐ and double‐base propellants was investigated by Fourier Transform Infrared (FTIR) Microspectroscopy. The observed diffusion phenomena were explained sufficiently well by the 2nd Fickian diffusion equation. The determined diffusion coefficient values ranged between 10−17 m2/s and 10−14 m2/s at 71 °C. Polymeric deterrents were found to diffuse about one order of magnitude slower than deterrents of small molecular weight in the same propellant matrix. The diffusion velocities of the deterrents investigated increased by about 2 orders of magnitude between single and double base propellants. The changes in the interior ballistic behaviour caused by long‐time storage could be correlated with the obtained deterrent diffusion coefficient values. The results of this study are in good agreement with the very few data about the solventless diffusion process of deterrents published before.
Equations for Predicting Cookoff Ignition Temperatures, heating times, and violence
Authors: Victor Andrew C. 
Published: May 2005

AbstractThis paper presents a simple closed‐form equation that can be used to predict autoignition behavior of energetic materials (EM) over a very wide range of heating rates. In many situations, this equation can be used in place of computer‐based numerical methods to calculate munition cookoff ignition temperatures and heating times.A simple model for predicting the violence of slow cookoff reactions that is also presented, matches small‐scale test data and demonstrates the elements that must be present in an a priori formulation of the problem.