The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The impetus for this research came from fundamental and applied questions connected with specified characteristics of Al nanopowders, theirs controlled syntheses and passivation, and their activity as high energetic ingredients in solid propulsion and in aluminum-water gels. Different conditions of powder syntheses by the exploding wire method and powder passivation were used: syntheses at low-pressure...
31 tetrazine's C-N heterocyclic derivativesbhave been investigated by density functional theory. Their optimized geometry structures, electronic structures, conjugation, molecular total energiesand heatsof formation(HOF) were calculated at the B3LYP/6-311G(d,p) level. The results show that most of the species keep a planar structure and exist considerable conjugation over the whole molecule, whichbenhances...
A set of 30 different molecular structures generally confirms that the sensitivity usually increases with increasing the value of detonation energy. This can be influenced by several factors depending on the type of crystal structure and on the properties depending on mutual interactions among the molecules in the crystal. In this work, the influence of hydrogen bond interactions on decreasing sensitivity...
This paper deals with the problem of transformation and practical utilisation of explosion energy. A principle has been suggested and described that enables utilisation of detonation energy of condensed explosive used as energy source exerting shock wave strain upon piezoelectric sample cut prepared from the oxide system PbO-TiO2-ZrO2. The piezoceramic transducer used as generator of impulse electric...
The synthesis of LLM-105 (2,6-diamino-3,5-dinitropyrazine 1-oxide) via the direct nitration of 2,6-diaminopyrazine 1-oxide is reported. Two synthetic routes to the starting material 2,6-diaminopyrazine 1-oxide have been investigated. The synthesis of 2,6-diamino-3,5-dinitropyrazine by nitration of 2,6-diaminopyrazine and 2,6-diacetamidopyrazine has also been studied. Whilst mono-nitration of 2,6-diaminopyrazine...
An ESZ KTTV instrument of a new, relatively simple construction has been applied to determination of electric spark sensitivity (EES) of 34 polynitro arenes and their derivatives. Results obtained are compared with those from measurements by means of older RDAD instrument. The analysis of relationship between the EES values obtained by measurements on the two instruments revealed that the relationship...
HNIW(CL-20), HMX and RDX have been examined in the small scale underwater test. Pressure curves of detonating materials were obtained. The comparison between HNIW, HMX and RDX pressure waves parameters were estimated. Applicability of the small scale underwater test for high explosives examining became proved.
The exothermic decompositions of the tosyl azide 1 and two diazides, 4,4'-diazidodiphenyl ether, (N3C6H4)2O 2 and 4,4'-diazidodiphenyl sulfide, (N3C6H4)2S (3), were studied theoretically using the CHETAH protocol, and experimentally using DSC, weight loss TGA-FTIR and C80-FTIR techniques. Numerical modelling and MS-spectroscopy were also performed to estimate the nature of the intrinsic molecular...
This article describes the thermal decomposition of n-Butyl-nitratoethylnitramine (Bu-NENA) which is a relatively new, not very widely used energetic plasticizer having attractive features. The decomposition reaction is a hydrolysis which leads to the formation of n-Butyl-ethanolnitramine (Bu-ENA) and nitric acid. stability of Bu-NENA can be measured by the Bu-ENA formation rate and by microcalorimetry...
Several new caprolactam-based Bronsted acidic ionic liquids [Caprolactam]X (X- = pTSO-, BSO-, BF4-, NO3-) with relatively lower cost and lower toxicity were synthesized and for the first time used in catalyzing organic reaction. They showed good catalytic activity in the nitration of toluene and chlorobenzene with HNO3/Ac2O under mild conditions. Among them, [Caprolactam]pTSO was the best one probably...
Four bacterial strains capable of growing on nitrotoluenes were incubated in basal salt medium containing either 2,4,6-trinitrotoluene (TNT) or its alkali hydrolysate (starting pH 12; duration 24 h) as carbon sources. The bacterial strains were identified as Burkholderia cepacia SH-1, Pseudomonas aeruginosa SH-2, Pseudomonas putida MC-I, and Pseudomonas sp. X. Burkholderia cepacia SH-1 was able to...
We have investigated computationally (B3PW91/6-31G**) the effects of electric fields upon certain properties - dipole moments, energies, geometries and electrostatic potentials – of two prototypical energetic molecules, nitromethane and dimethylnitramine. Fields of various strengths and in different directions were considered. The stronger fields significantly polarized the molecular charge distributions,...
An ESZ KTTV instrument of a new, relatively simple construction has been applied to the determination of electric spark sensitivity (EES) of 31 polynitro arenes and their derivatives. Results obtained are compared with the theoretical DFT B3LYP/6-31G(d,p) Mulliken net charges of nitro groups, QNO2, which primarily react in the initiation by the spark. On the basis of analysis of the results obtained...
The solid catalysts of SO4 2-/TiO2, SO4 2-/TiO2-ZrO2, SO4 2-/WO3-ZrO2, and SO4 2-/MoO3-ZrO2 have been prepared and regioselectiveties of chlorobenzene minonitration on these catalysts were investigated. When the reaction was carried out at 30 C for 30 min, SO4 2-/TiO2-ZrO2(1:1) by a calcination step for 3 h at 550 C enhanced the para-selectivity of chlorobenzene nitration by using nitric acid as nitrating...
On the basis of the earlier methodology developed for generation of thermal decomposition mechanisms for organic compounds, computer simulation of trans-1,4,5,8-tetranitrodecahydro-pyrazino[2,3-b]pyrazine (TNAD) degradation is performed. The probable pathways of this decomposition are examined. The activation energies of reactions at the initial step of TNAD degradation are calculated using the B3LYP/6-31G*...
Classification of thermolysis mechanisms for C-nitrocompounds has been performed based on empirical data for different classes of chemical compounds. Focus was placed on the functional environment surrounding the nitrogroup of interest. Finding specific structural characteristics allowed us to formalize the possible mechanisms of its degradation. The results of subsequent computer generation for decomposition...
Low velocity impacts are a source of explosive accidents. Several different mechanisms may be concurrently responsible for the initiation. Studying the effects of low velocity, comparatively long duration, impacts on energetic materials can assist in the development of explosive safety procedures and Insensitive Munitions. Careful design of the target configuration can eliminate some of the problems...
Energy transfer mechanisms to internal molecular degrees of freedom in shock and detonation waves in polyatomic liquids are investigated. The proposed approach uses a new version of the method of nonequilibrium molecular dynamics based on the simplest model potential energy surfaces of reacting polyatomic molecules. The main feature is adaptation of some results and approaches of gas theory to liquids...
Catastrophic initiation of an energetic material consists of a complex, interactive, sequential train of mechanistic mechanical, physical, and chemical processes which occur over a finite time period and proceed from macroscopic into sub-microscopic composition levels (bulk > crystalline > molecular > atomic). Initiation results when these processes proceed at a rate which generates sufficient...
In the paper the linear form of burning rate law r=r1źp, describing changes (in proportion to pressure p) in burning rate of propellants is reviewed. The linear form is one of many (but very popular) forms of burning rate law predicted to analysis and computer simulations of propellant gun systems operating and design process of gun. Coeffcient r1 of the linear form is usually calculated on the basis...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.