scholarly journals Comparative Studies on Thermal Decompositions of Dinitropyrazole-Based Energetic Materials

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 7004
Author(s):  
Jing Zhou ◽  
Chongmin Zhang ◽  
Huan Huo ◽  
Junlin Zhang ◽  
Zihui Meng ◽  
...  
Keyword(s):  
Energetic Materials ◽  
Hydrogen Transfer ◽  
Thermal Studies ◽  
Thermal Stabilization ◽  
Kinetic Studies ◽  
Physicochemical Characteristics ◽  
Release Process ◽  
Gaseous Products ◽  
Design And Synthesis ◽  
Nitrogen Bonds

Dinitropyrazole is an important structure for the design and synthesis of energetic materials. In this work, we reported the first comparative thermal studies of two representative dinitropyrazole-based energetic materials, 4-amino-3,5-dinitropyrazole (LLM-116) and its novel trimer derivative (LLM-226). Both the experimental and theoretical results proved the active aromatic N-H moiety would cause incredible variations in the physicochemical characteristics of the obtained energetic materials. Thermal behaviors and kinetic studies of the two related dinitropyrazole-based energetic structures showed that impressive thermal stabilization could be achieved after the trimerization, but also would result in a less concentrated heat-release process. Detailed analysis of condensed-phase systems and the gaseous products during the thermal decomposition processes, and simulation studies based on ReaxFF force field, indicated that the ring opening of LLM-116 was triggered by hydrogen transfer of the active aromatic N-H moiety. In contrast, the initial decomposition of LLM-226 was caused by the rupture of carbon-nitrogen bonds at the diazo moiety.

3-R-4-(5-methyleneazide-1,2,4-oxadiazol-3-yl)furazan and its ionic salts as low-sensitivity and high-detonation energetic materials

2021 ◽  
Author(s):  
Rui Yang ◽  
Yifei Liu ◽  
Zhen Dong ◽  
Haiyan Li ◽  
Zhiwen Ye
Keyword(s):  
Melting Point ◽  
Energetic Materials ◽  
Environmentally Friendly ◽  
Azide Group ◽  
Design And Synthesis ◽  
Ionic Salts ◽  
Low Sensitivity

As an environmentally friendly energetic group, the azide group can not only control the melting point but also increase the energy of the compound. Therefore, the design and synthesis of...

Design and synthesis of novel pyridazine N-aryl acetamides: In-vitro evaluation of α-glucosidase inhibition, docking, and kinetic studies

2020 ◽  
Vol 102 ◽  
pp. 104071
Author(s):  
Setareh Moghimi ◽  
Mahsa Toolabi ◽  
Somayeh Salarinejad ◽  
Loghman Firoozpour ◽  
Seyed Esmaeil Sadat Ebrahimi ◽  
...  
Keyword(s):  
Kinetic Studies ◽  
In Vitro Evaluation ◽  
Design And Synthesis

Thermal Decomposition of Energetic Materials 26. Simultaneous Temperature Measurements of the Condensed Phase and Rapid-Scan FT-IR Spectroscopy of the Gas Phase at High Heating Rates

1987 ◽  
Vol 41 (7) ◽  
pp. 1147-1151 ◽  
Author(s):  
J. T. Cronin ◽  
T. B. Brill
Keyword(s):  
Real Time ◽  
Condensed Phase ◽  
Energetic Materials ◽  
Buffer Gas ◽  
Heating Rates ◽  
Decomposition Products ◽  
Gaseous Products ◽  
Rapid Scan ◽  
Ft Ir ◽  
Better Than

Rapid-scan infrared spectroscopy (RSFT-IR) with better than 100-ms temporal resolution has been used to quantify the gas decomposition products of energetic materials in real time at various heating rates up to 800°C/s and under buffer gas pressures of 1 to 1000 psi. A new method is described that permits simultaneous real-time recording of the temperature of the condensed phase and of the IR spectra of the gaseous products under the above conditions. Endothermic and exothermic events in the condensed phase can now be correlated with the evolved gases under conditions approaching those of combustion. The design and procedure for using the cell are given and are applied to the thermolysis of 1,7-diazido-2,4,6-trinitro-2,4,6-triazaheptane (DATH) and pentaery-thrityltetrammonium nitrate (PTTN).

Design and Synthesis of Energetic Materials

2001 ◽  
Vol 31 (1) ◽  
pp. 291-321 ◽  
Author(s):  
Laurence E Fried ◽  
M Riad Manaa ◽  
Philip F Pagoria ◽  
Randall L. Simpson
Keyword(s):  
Energetic Materials ◽  
Design And Synthesis

Surface Chemical Characterization Methods Applied to Energetic Materials

1992 ◽  
Vol 296 ◽  
Author(s):  
B. C. Beard ◽  
I. Sharma
Keyword(s):  
Photoelectron Spectroscopy ◽  
Energetic Materials ◽  
Chemical Characterization ◽  
Surface Chemical ◽  
Specific Chemical ◽  
Surface Mass ◽  
Characterization Methods ◽  
Gaseous Products ◽  
Increased Sensitivity ◽  
And Performance

AbstractThe reaction chemistry of energetic materials is often considered only with respect to the types and quantities of gaseous products formed. For a thorough understanding of the initi reaction steps, that largely determine the sensitivity of the material, both gaseous and solid products must be determined. In addition, it is the solid state partial decomposition intermediates remaining in a damaged material that can lead to increased sensitivity. The preference for the initial reactions to take place at the surface of particles and the low concentrations of intermediates formed demands the use of highly sensitive surface specific chemical probe techniques. State of the art surface chemical techniques will be discussed, focusing on x-ray photoelectron spectroscopy and surface mass spectrometry. Principles of operation and performance will be highlighted, comparisons will be made to bulk chemical analysis, and examples of applications will be presented.

scholarly journals Initial Decomposition Mechanism of 3-Nitro-1,2,4-triazol-5-one (NTO) under Shock Loading: ReaxFF Parameterization and Molecular Dynamic Study

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4808
Author(s):  
Lixiaosong Du ◽  
Shaohua Jin ◽  
Pengsong Nie ◽  
Chongchong She ◽  
Junfeng Wang
Keyword(s):  
Molecular Dynamic ◽  
Particle Velocity ◽  
Energetic Materials ◽  
Hydrogen Transfer ◽  
Shock Loading ◽  
Computational Cost ◽  
Shock Velocity ◽  
Decomposition Mechanism ◽  
Velocity Equation ◽  
Dissociation Curves

We report a reactive molecular dynamic (ReaxFF-MD) study using the newly parameterized ReaxFF-lg reactive force field to explore the initial decomposition mechanism of 3-Nitro-1,2,4-triazol-5-one (NTO) under shock loading (shock velocity >6 km/s). The new ReaxFF-lg parameters were trained from massive quantum mechanics data and experimental values, especially including the bond dissociation curves, valence angle bending curves, dihedral angle torsion curves, and unimolecular decomposition paths of 3-Nitro-1,2,4-triazol-5-one (NTO), 1,3,5-Trinitro-1,3,5-triazine (RDX), and 1,1-Diamino-2,2-dinitroethylene (FOX-7). The simulation results were obtained by analyzing the ReaxFF dynamic trajectories, which predicted the most frequent chain reactions that occurred before NTO decomposition was the unimolecular NTO merged into clusters ((C2H2O3N4)n). Then, the NTO dissociated from (C2H2O3N4)n and started to decompose. In addition, the paths of NO2 elimination and skeleton heterocycle cleavage were considered as the dominant initial decomposition mechanisms of NTO. A small amount of NTO dissociation was triggered by the intermolecular hydrogen transfer, instead of the intramolecular one. For α-NTO, the calculated equation of state was in excellent agreement with the experimental data. Moreover, the discontinuity slope of the shock-particle velocity equation was presented at a shock velocity of 4 km/s. However, the slope of the shock-particle velocity equation for β-NTO showed no discontinuity in the shock wave velocity range of 3–11 km/s. These studies showed that MD by using a suitable ReaxFF-lg parameter set, could provided detailed atomistic information to explain the shock-induced complex reaction mechanisms of energetic materials. With the ReaxFF-MD coupling MSST method and a cheap computational cost, one could also obtain the deformation behaviors and equation of states for energetic materials under conditions of extreme pressure.

Kinetische Untersuchungen und Charakterisierung der solubilisierten Oestradiol-bzw. Testosteron-"sensitiven" 17 β-HSD-Aktivitäten / Microsome-Associated 17β-Hydroxysteroid Dehydrogenases of Human Placenta, II Kinetic Studies and Characterization of the Solubilized Estradioland Testosterone-“Sensitive” 17β-HSD-Activities

1975 ◽  
Vol 30 (1-2) ◽  
pp. 17-24 ◽  
Author(s):  
Kunhard Pollow ◽  
Wilfried Runge ◽  
Barbara Pollow
Keyword(s):  
Steroid Hormones ◽  
Human Placenta ◽  
Hydrogen Transfer ◽  
Kinetic Studies ◽  
Integrated System ◽  
The Other ◽  
Effect Of Temperature ◽  
Ph Optimum ◽  
Hydroxysteroid Dehydrogenases ◽  
Estradiol 17Β

Abstract Detailed enzyme kinetic parameters of the reactions catalyzed by the two 17β-hydroxysteroid dehydrogenases (17β-HSD), which were solubilized from the microsomes of human placenta by treatment with phospholipase A, followed by enrichment and separation were determined. Both enzymes are strictly substrate specific. The most active substrate of one of the 17β-HSD (fraction A) is estradiol-17β, the other 17β-HSD (fraction B) is sensitive to testosterone. Both NAD and NADP can serve as hydrogen transferring coenzymes, the latter giving about one-third of the initial rate of the former. With respect to the influence of temperature, different buffers and pH values, Michaelis constants [Km] with estradiol-17β and testosterone as substrates, the solubilized and separated microsomal 17β-HSD behave like those isolated from the cytoplasmic fraction. The two 17β-HSD, after solubilization from the microsomal fraction of human placenta, enrichment and separation from each other, show only a little activity for the transfer of hydrogen between C17 of estradiol-17β and C17 of androstenedione. On the other hand, intact microsomes and an integrated system prepared by recombination of the 17β-enzymes by preincubation in phosphate buffer are able to catalyse very actively the transfer of hydrogen between estradiol-17β and androstenedione. The effect of temperature and time on the recombination of the two enriched and separated microsomal enzyme activities and the determination of the pH-optimum of the hydrogen transfer reaction are described. Finally it is proposed that the hydrogen transfer between steroid hormones represents an aspect of the true reaction mechanism of steroid hormones: Steroid hormones function as hydrogen transferring coenzymes by forming part of a chain of hydrogen carriers.

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