Improved reliable approach to predict melting points of energetic compounds

2011 ◽  
Vol 308 (1-2) ◽  
pp. 114-128 ◽  
Author(s):  
Mohammad Hossein Keshavarz ◽  
Farhad Gharagheizi ◽  
Hamid Reza Pouretedal
Keyword(s):  
Energetic Compounds ◽  
Melting Points

Reliable method for safety assessment of melting points of energetic compounds

2016 ◽  
Vol 103 ◽  
pp. 10-22 ◽  
Author(s):  
Masood Hamadanian ◽  
Mohammad Hossein Keshavarz ◽  
Behzad Nazari ◽  
Mostafa Mohebbi
Keyword(s):  
Safety Assessment ◽  
Reliable Method ◽  
Energetic Compounds ◽  
Melting Points

Exploration of low-melting energetic compounds: influence of substituents on melting points

2020 ◽  
Vol 44 (32) ◽  
pp. 13576-13583
Author(s):  
Rui Yang ◽  
Zhen Dong ◽  
Zhiwen Ye
Keyword(s):  
Melting Point ◽  
Substituent Effect ◽  
Energetic Compounds ◽  
Melting Points ◽  
Explosive Performance ◽  
Influence Of Substituents

The substituent effect of low melting point compounds reduces sensitivity and improves explosive performance.

A simple method to predict melting points of non-aromatic energetic compounds

2010 ◽  
Vol 292 (1-2) ◽  
pp. 1-6 ◽  
Author(s):  
Reza Fareghi Alamdari ◽  
Mohammad Hossein Keshavarz
Keyword(s):  
Energetic Compounds ◽  
Melting Points ◽  
Simple Method

scholarly journals 5-Nitrotetrazol and 1,2,4-Oxadiazole Methylene-Bridged Energetic Compounds: Synthesis, Crystal Structures and Performances

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7072
Author(s):  
Jiarong Zhang ◽  
Fuqiang Bi ◽  
Zhi Yang ◽  
Qi Xue ◽  
Bozhou Wang
Keyword(s):  
Structural Type ◽  
Energetic Compounds ◽  
X Ray Diffraction ◽  
Melting Points ◽  
Thermal Stabilities ◽  
X Ray ◽  
Apparent Activation Energies ◽  
The Impact ◽  
First Time ◽  
Impact Sensitivities

A new structural type for melt cast materials was designed by linking nitrotetrazole ring with 1,2,4-oxadiazole through a N-CH2-C bridge for the first time. Three N-CH2-C linkage bridged energetic compounds, including 3-((5-nitro-2H-tetrazol-2-yl) methyl)-1,2,4-oxadiazole (NTOM), 3-((5-nitro-2H-tetrazol-2-yl)methyl)-5-(trifluoromethyl)-1,2,4 -oxadiazole (NTOF) and 3-((5-nitro-2H-tetrazol-2-yl)methyl)-5-amine-1,2,4-oxadiazole (NTOA), were designed and synthesized through a two-step reaction by using 2-(5-nitro-2H-tetrazole -2-yl)acetonitrile as the starting material. The synthesized compounds were fully characterized by NMR (1H, 13C), IR spectroscopy and elemental analysis. The single crystals of NTOM, NTOF and NTOA were successfully obtained and investigated by single-crystal X-ray diffraction. The thermal stabilities of these compounds were evaluated by DSC-TG measurements, and their apparent activation energies were calculated by Kissinger and Ozawa methods. The crystal densities of the three compounds were between 1.66 g/cm3 (NTOA) and 1.87 g/cm3 (NTOF). The impact and friction sensitivities were measured by standard BAM fall-hammer techniques, and their detonation performances were computed using the EXPLO 5 (v. 6.04) program. The detonation velocities of the three compounds are between 7271 m/s (NTOF) and 7909 m/s (NTOM). The impact sensitivities are >40 J, and the friction sensitivities are >360 N. NTOM, NTOF and NTOA are thermally stable, with decomposition points > 240 °C. The melting points of NTOM and NTOF are 82.6 °C and 71.7 °C, respectively. Hence, they possess potential to be used as melt cast materials with good thermal stabilities and better detonation performances than TNT.

Study on the synthesis of 2-fluoro-2,2-dinitroethyl esters as a potential melt cast matrix in explosive charges

2017 ◽  
Vol 41 (21) ◽  
pp. 12700-12706 ◽  
Author(s):  
Jinchao Ma ◽  
Hongwei Yang ◽  
Guangbin Cheng
Keyword(s):  
Detonation Properties ◽  
Energetic Compounds ◽  
Melting Points ◽  
Thermal Stabilities ◽  
Explosive Charges

Polynitro energetic compounds with low melting points, high thermal stabilities, good detonation properties, and considerably mechanical insensitivities are reported; some of these compounds are promising potential replacements of TNT used in melt cast explosives.

Non-Plasmonic SERS with Silicon: Is It Really Safe? New Insights into Opto-Thermics of Core/Shell Microbeads

2018 ◽  
Author(s):  
Nicolò Bontempi ◽  
Irene Vassalini ◽  
Stefano Danesi ◽  
Matteo Ferroni ◽  
Paolo Colombi ◽  
...  
Keyword(s):  
Critical Role ◽  
Raman Laser ◽  
Core Shell ◽  
Thermal Coupling ◽  
Melting Points ◽  
Experimental Proof ◽  
Weakly Coupled ◽  
Light Management ◽  
Laser Sources ◽  
First Time

<p>Here we investigate for the first time the opto-thermal behavior of SiO<sub>2</sub>/Si core/shell microbeads (Si-rex) irradiated with three common Raman laser sources (lambda=532, 633, 785 nm) under real working conditions. We obtained an experimental proof of the critical role played by bead size and aggregation in heat and light management, demonstrating that in the case of strong opto-thermal coupling the temperature can exceed that of the melting points of both core and shell components. In addition, we also show that weakly coupled beads can be utilized as stable substrates for plasmon-free SERS experiments.</p>

Some Computationally-Predicted Properties of a Group of Proposed Energetic Compounds.

1996 ◽  
Author(s):  
Peter Politzer ◽  
Pat Lane ◽  
M. E. Grice
Keyword(s):  
Energetic Compounds

Biotransformation of nitrocellulose under methanogenic conditions

1996 ◽  
Vol 34 (5-6) ◽  
pp. 327-334 ◽  
Author(s):  
David L. Freedman ◽  
Bryan M. Caenepeel ◽  
Byung J. Kim
Keyword(s):  
Biological Treatment ◽  
Enrichment Culture ◽  
Basal Medium ◽  
Anaerobic Biodegradation ◽  
Anaerobic Treatment ◽  
Acid Digestion ◽  
Energetic Compounds ◽  
Nitrate Ester ◽  
Digestion Technique ◽  
Aerobic And Anaerobic

Treatment of wastewater containing nitrocellulose (NC) fines is a significant hazardous waste problem currently facing manufacturers of energetic compounds. Previous studies have ruled out the use of biological treatment, since NC has appeared to be resistant to aerobic and anaerobic biodegradation. The objective of this study was to examine NC biotransformation in a mixed methanogenic enrichment culture. A modified cold-acid digestion technique was used to measure the percentage of oxidized nitrogen (N) remaining on the NC. After 11 days of incubation in cultures amended with NC (10 g/L) and methanol (9.9 mM), the % N (w/w) on the NC decreased from 13.3% to 10.1%. The presence of NC also caused a 16% reduction in methane output. Assuming the nitrate ester on NC was reduced to N2, the decrease in CH4 represented almost exactly the amount of reducing equivalents needed for the observed decrease in oxidized N. An increase in the heat of combustion of the transformed NC correlated with the decrease in % N. There was no statistically significant decrease in % N when only NC was added to the culture, or in controls that contained only the sulfide-reduced basal medium. The biotransformed NC has a % N comparable to nonexplosive nitrated celluloses, suggesting that anaerobic treatment may be a technically feasible process for rendering NC nonhazardous.

Separation and Characterization of Standard Propoxyphene Diastereomers and Their Determination in Pharmaceutical and Illicit Preparations

1981 ◽  
Vol 64 (4) ◽  
pp. 875-883
Author(s):  
Shiv K Soni ◽  
Daniel Van Gelder
Keyword(s):  
High Pressure ◽  
Optical Isomers ◽  
Gold Chloride ◽  
Melting Points ◽  
Eutectic Melting ◽  
Racemic Mixtures ◽  
The Individual ◽  
Isomeric Mixtures ◽  
Asymmetric Carbon

Abstract Due to the existence of 2 asymmetric carbon atoms in: the propoxyphene molecule, there are 4 diastereomers: alpha dextro, alpha levo, beta dextro, and beta levo. Only α-d-propoxyphene is included under the federal Controlled Substances Act. Baseline separations of propoxyphene from various incipients (aspirin, caffeine, phenacetin, and acetaminophen) present in pharmaceutical and illicit preparations, and between the alpha and beta diastereomers, were achieved by high pressure liquid chromatography. The column eluant was collected and propoxyphene was extracted. The optical isomers were differentiated and characterized by melting points and by chemical microcrystalline tests. Using hot stage thermomicroscopy, the eutectic melting points of binary isomeric mixtures of propoxyphene bases and salts were found to be depressed about 10° and 15-30°C, respectively, below the individual isomer melting points. The characteristic microcrystals formed with the alpha racemic mixtures by using a glycerin-aqueous gold chloride reagent were not produced by the beta racemic mixtures.

scholarly journals Synthesis, antibiotic structure–activity relationships, and cellulose dissolution studies of new room-temperature ionic liquids derived from lignin

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shihong Liu ◽  
Michael Gonzalez ◽  
Celine Kong ◽  
Scott Weir ◽  
Aaron M. Socha
Keyword(s):  
Antibacterial Activity ◽  
Ionic Liquids ◽  
Room Temperature ◽  
Oxidation Products ◽  
Cellulose Dissolution ◽  
Melting Points ◽  
E Coli ◽  
Alkyl Chains ◽  
Renewable Feedstocks ◽  
Commodity Chemicals

Abstract Background Ionic liquids (ILs) are promising pretreatment solvents for lignocellulosic biomass, but are largely prepared from petroleum precursors. Benzaldehydes from depolymerized lignin, such as vanillin, syringaldehyde, and 4-methoxy benzaldehyde, represent renewable feedstocks for the synthesis of ionic liquids. We herein report syntheses of novel lignin-derived ionic liquids, with extended N-alkyl chains, and examine their melting points, cellulose dissolution capacities, and toxicity profiles against Daphnia magna and E. coli strain 1A1. The latter organism has been engineered to produce isoprenol, a drop-in biofuel and precursor for commodity chemicals. Results The new N,N-diethyl and N,N-dipropyl methyl benzylammonium ILs were liquids at room temperature, showing 75–100 °C decreased melting points as compared to their N,N,N-trimethyl benzylammonium analog. Extension of N-alkyl chains also increased antibacterial activity threefold, while ionic liquids prepared from vanillin showed 2- to 4-fold lower toxicity as compared to those prepared from syringaldehyde and 4-methoxybenzaldehyde. The trend of antibacterial activity for anions of lignin-derived ILs was found to be methanesulfonate < acetate < hydroxide. Microcrystalline cellulose dissolution, from 2 to 4 wt% after 20 min at 100 °C, was observed in all new ILs using light microscopy and IR spectroscopy. Conclusions Ionic liquids prepared from H-, S- and G-lignin oxidation products provided differential cytotoxic activity against E. coli and D. magna, suggesting these compounds could be tailored for application specificity within a biorefinery.

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