Introduction of the acylamino group to bridged bis(nitroamino-1,2,4-triazole): a strategy for tuning the sensitivity of energetic materials

2021 ◽  
Vol 45 (38) ◽  
pp. 18059-18064
Author(s):  
Dongxu Chen ◽  
Jiangshan Zhao ◽  
Hongwei Yang ◽  
Hao Gu ◽  
Guangbin Cheng
Keyword(s):  
Energetic Materials ◽  
Energetic Material

Introduction of the acylamino group into energetic material compounds will contribute to balancing the sensitivity and the energy.

Achieving tunable chemical reactivity through photo-initiation of energetic materials at metal oxide surfaces

2020 ◽  
Vol 22 (43) ◽  
pp. 25284-25296
Author(s):  
Maija M. Kuklja ◽  
Roman Tsyshevsky ◽  
Anton S. Zverev ◽  
Anatoly Mitrofanov ◽  
Natalya Ilyakova ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Chemical Reactions ◽  
Energetic Materials ◽  
Chemical Reactivity ◽  
Energetic Material ◽  
Oxide Surfaces ◽  
Oxide Interfaces ◽  
Metal Oxide Surfaces

Photo-stimulated chemical reactions in energetic materials can be highly controlled by selectively designing energetic material – metal oxide interfaces with tailored properties.

Solidification Heat Transfer and Base Separation Analysis in the Casting of an Energetic Material in a Projectile

2005 ◽  
Author(s):  
Dawei Sun ◽  
S. Ravi Annapragada ◽  
Suresh V. Garimella ◽  
Sanjeev Sing
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Numerical Model ◽  
Residual Stresses ◽  
Energetic Materials ◽  
Energetic Material ◽  
Complex Geometries ◽  
Experimental Measurements ◽  
Linear Temperature ◽  
High Prandtl Number

This paper investigates the problem of base separation in the casting of energetic materials in a projectile. Special challenges that arise in casting high Prandtl number energetic materials in projectiles of complex geometries are addressed. A comprehensive numerical model is developed by integrating finite volume and finite element methods to analyze the thermal and flow fields as well as the residual stresses. The predictions, which are confirmed by experimental measurements, suggest that sustenance of a linear temperature profile along the projectile axis can eliminate base separation, and also reduce residual stresses in the final casting.

scholarly journals Nanostructured Energetic Materials with Sol-gel Methods

2003 ◽  
Vol 800 ◽  
Author(s):  
Alexander E. Gash ◽  
Joe H. Satcher ◽  
Randall L. Simpson ◽  
Brady J. Clapsaddle
Keyword(s):  
Thermal Properties ◽  
Energetic Materials ◽  
Energetic Material ◽  
Sol Gel ◽  
Small Scale ◽  
Fine Grained ◽  
Electron Microscopies ◽  
Burn Rate ◽  
Scanning Electron

AbstractThe utilization of sol-gel chemical methodology to prepare nanostructured energetic materials as well as the concepts of nanoenergetics is described. The preparation and characterization of two totally different compositions is detailed. In one example, nanostructured aerogel and xerogel composites of sol-gel iron (III) oxide and ultra fine grained aluminum (UFG Al) are prepared, characterized, and compared to a conventional micron-sized Fe2O3/Al thermite. The exquisite degree of mixing and intimate nanostructuring of this material is illustrated using transmission and scanning electron microscopies (TEM and SEM). The nanocomposite material has markedly different energy release (burn rate) and thermal properties compared to the conventional composite, results of which will be discussed. Small-scale safety characterization was performed on the nanostructured thermite. The second nanostructured energetic material consists of a nanostructured hydrocarbon resin fuel network with fine ammonium perchlorate (NH4ClO4) oxidizer present.

Kinetic Compensation Effect of Kinetic Parameters of Thermal Explosion Test

2012 ◽  
Vol 184-185 ◽  
pp. 1408-1417
Author(s):  
Ying Hui Shao ◽  
Zi Ru Liu ◽  
Xiao Ning Ren ◽  
Shu Yun Heng ◽  
Pu Yue ◽  
...  
Keyword(s):  
Kinetic Parameters ◽  
Thermal Explosion ◽  
Energetic Materials ◽  
Compensation Effect ◽  
Energetic Material ◽  
Regression Equation ◽  
Kinetic Temperature ◽  
Single Compound ◽  
Main Component ◽  
Explosion Test

The kinetic parameters of thermal explosion tests with five-second delay for 273 energetic materials were analyzed. The compensation effect exists between the two thermal explosion kinetic parameters of these energetic materials, e.g. lnA and Eb. The kinetic parameters of these energetic materials can be expressed by a single linear regression equation for the single compound or mixture under all conditions. The slopes of the regression equation for various systems are in the range from 0.1952 to 0.2413 (mol•kJ-1). The regression equation for single compound or mixture with one type of energetic material as main component has better linearity. Therefore, their “iso-kinetic temperature” Tik is close to their thermal explosion temperature Tb and the “iso-kinetic delay period”τik is also close to the 5 seconds.

Molecular Composition, Structure, and Sensitivity of Explosives

1992 ◽  
Vol 296 ◽  
Author(s):  
Carlyle B. Storm ◽  
James R. Travis
Keyword(s):  
Molecular Structure ◽  
Hot Spots ◽  
Energetic Materials ◽  
Physical State ◽  
Hot Spot ◽  
Energetic Material ◽  
Specific Situation ◽  
Reaction Products ◽  
Ambient Conditions ◽  
Delayed Reaction

AbstractHigh explosives, blasting agents, propellants, and pyrotechnics are all metastable relative to reaction products and are termed energetic materials. They are thermodynamically unstable but the kinetics of decomposition at ambient conditions are sufficiently slow that they can be handled safely under controlled conditions. The ease with which an energetic material can be caused to undergo a violent reaction or detonation is called its sensitivity. Sensitivity tests for energetic materials are aimed at defining the response of the material to a specific situation, usually prompt shock initiation or a delayed reaction in an accident. The observed response is always due to a combination of the physical state and the molecular structure of the material. Modeling of any initiation process must consider both factors. The physical state of the material determines how and where the energy is deposited in the material. The molecular structure in the solid state determines the mechanism of decomposition of the material and the rate of energy release. Slower inherent reaction chemistry leads to longer reaction zones in detonation and inherently safer materials. Slower chemistry also requires hot spots involved in initiation to be hotter and to survive for longer periods of time. High thermal conductivity also leads to quenching of small hot spots and makes a material more difficult to initiate. Early endothermic decomposition chemistry also delays initiation by delaying heat release to support hot spot growth. The growth to violent reaction or detonation also depends on the nature of the early reaction products. If chemical intermediates are produced that drive further accelerating autocatalytic decomposition the initiation will grow rapidly to a violent reaction.

Energetic materials: α-NTO crystallizes as a four-component triclinic twin

2005 ◽  
Vol 61 (5) ◽  
pp. 577-584 ◽  
Author(s):  
Nadezhda Bolotina ◽  
Kristin Kirschbaum ◽  
A. Alan Pinkerton
Keyword(s):  
Energetic Materials ◽  
Crystal Packing ◽  
Energetic Material ◽  
Data Sets ◽  
Flat Chain ◽  
Planar Molecules ◽  
Triclinic Unit Cell ◽  
Symmetry Space ◽  
Symmetry Space Group ◽  
Additional Hydrogen

The prevalent polymorph of the energetic material 5-nitro-2,4-dihydro-1,2,4,-triazol-3-one, α-NTO, crystallizes as a four-component twin with triclinic symmetry (space group P\bar 1). All crystals under investigation were fourlings, i.e. they contained each of the four possible twin components. Complete data sets were collected for two crystals, one with a predominant amount of one individual component (55%) and one with approximately equal volumes of each component. In both cases the fourling components are related by the twofold axes inherent in the holohedral symmetry of a pseudo-orthorhombic superlattice with a o = a t , b o = b t and c o = a t + b t + 2c t . The triclinic unit cell contains four crystallographically independent planar molecules in the asymmetric unit, each of which forms a hydrogen-bonded flat chain parallel to a t . Pairs of chains are combined into planar ribbons by additional hydrogen bonds. Thus, two independent ribbons extend parallel to a t , creating a dihedral angle of ∼ 70°. The origin of the twinning is derived from consideration of the crystal packing and the hydrogen-bonding scheme.

The thermochemistry and reaction pathways of energetic material decomposition and combustion

1992 ◽  
Vol 339 (1654) ◽  
pp. 365-376 ◽  
Keyword(s):  
Condensed Phase ◽  
Energetic Materials ◽  
Energetic Material ◽  
Theoretical Method ◽  
Chemical Processes ◽  
Reaction Pathways ◽  
Quantum Chemical Methods ◽  
Solvation Energies ◽  
Moller Plesset ◽  
Ignition And Combustion

The chemical processes involved in the decomposition and combustion of energetic materials have been investigated theoretically using quantum chemical methods to determine the thermochemistry and reaction pathways. The Bond-Additivity-Corrected Moller-Plesset fourth-order perturbation theory method (BAC-MP4) has been used to determine heats of formation and free energies of reaction intermediates of decomposition and combustion. In addition, the BAC-MP4 method has been used to determine reaction pathways involving these intermediates. A theoretical method for calculating solvation energies has been developed to treat the non-idealities of high pressure and the condensed phase. The resulting chemical processes involving decomposition, ignition and combustion are presented for nitramines and nitromethane. Differences in decomposition mechanisms for the condensed phase and gas phase are discussed. In addition, we discuss the effects that amines can have on the initial stages of condensed-phase nitromethane decomposition. Bond dissociation energies for nitro-triazoles are compared with those of other nitro compounds.

Shear Initiated Reactions in Energetic and Reactive Materials

2005 ◽  
Vol 896 ◽  
Author(s):  
Denise Meuken ◽  
Maria Martines Pacheco ◽  
Ries Verbeek ◽  
Richard Bouma ◽  
L Katgerman
Keyword(s):  
Shear Deformation ◽  
Energetic Materials ◽  
Large Scale ◽  
Reaction Rate ◽  
Large Deformations ◽  
Energetic Material ◽  
High Explosives ◽  
Reactive Materials ◽  
Fundamental Understanding

AbstractDeformation of energetic materials may cause undesired reactions and therefore hazardous situations. The deformation of an energetic material and in particular shear deformation is studied in this paper. Understanding of the phenomena leading to shear initiation is not only necessary to explain for example the response of munitions to intrusions or large deformations imposed in storage and transportation accidents. A fundamental understanding of shear initiation also provides the opportunity to initiate energetic materials in a different and controlled manner, and possibly with a tailored reaction rate of the material. Several small and large scale experiments have been performed in which a shear deformation is imposed onto high explosives as well as thermite based reactive materials. Experiments are numerically simulated in order to correlate small and large scale experiments and understand the initiation mechanisms.

scholarly journals Machine Learned Prediction of Reaction Template Applicability for Data-Driven Retrosynthetic Predictions of Energetic Materials

2020 ◽  
Author(s):  
Michael Fortunato ◽  
Connor W. Coley ◽  
Brian Barnes ◽  
Klavs F. Jensen
Keyword(s):  
Neural Network ◽  
Energetic Materials ◽  
Energetic Material ◽  
Training Data ◽  
Data Generation ◽  
Material Synthesis ◽  
Subgraph Matching ◽  
Planning Models ◽  
The Neural Network ◽  
Patent Literature

State of the art computer-aided synthesis planning models are naturally biased toward commonly reported chemical reactions, thus reducing the usefulness of those models for the unusual chemistry relevant to shock physics. To address this problem, a neural network was trained to recognize reaction template applicability for small organic molecules to supplement the rare reaction examples of relevance to energetic materials. The training data for the neural network was generated by brute force determination of template subgraph matching for product molecules from a database of reactions in U.S. patent literature. This data generation strategy successfully augmented the information about template applicability for rare reaction mechanisms in the reaction database. The increased ability to recognize rare reaction templates was demonstrated for reaction templates of interest for energetic material synthesis such as heterocycle ring formation.<div><br></div><div>The following article has been submitted to by the 21st Biennial APS Conference on Shock Compression of Condensed Matter. After it is published, it will be found at https://publishing.aip.org/resources/librarians/products/journals/.</div>

scholarly journals A promising insensitive energetic material based on a fluorodinitromethyl explosophore group and 1,2,3,4-tetrahydro-1,3,5-triazine: synthesis, crystal structure and performance

RSC Advances ◽  
2020 ◽  
Vol 10 (20) ◽  
pp. 11816-11822 ◽  
Author(s):  
Huan Huo ◽  
Junlin Zhang ◽  
Jun Dong ◽  
Lianjie Zhai ◽  
Tao Guo ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Energetic Materials ◽  
Energetic Material ◽  
Efficient Strategy ◽  
And Performance

The introduction of fluorodinitromethyl energetic groups is an efficient strategy to improve the performances of energetic materials.

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