The effects of H+, NH3OH+ and NH4+ on the thermal decomposition of bistetrazole N-oxide anion

2019 ◽  
Vol 21 (27) ◽  
pp. 15215-15221 ◽  
Author(s):  
Chuande Zhao ◽  
Yu Chi ◽  
Ying Xiong ◽  
Qian Yu ◽  
Xinfeng Wang ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Nitro Group ◽  
Detonation Velocity ◽  
Impact Sensitivity

Dihydroxylammonium 5,5′-bistetrazole-1,1′-diolate (TKX-50) has attracted great interest as it breaks through the limitations of the traditional nitro group, high detonation velocity and moderate impact sensitivity.

Sensitization of nitrocompounds by amines

1992 ◽  
Vol 339 (1654) ◽  
pp. 403-417 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Charge Transfer ◽  
Nitro Group ◽  
Picric Acid ◽  
Isotope Analysis ◽  
Ionization Mass ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Rate Determining Step ◽  
The Impact

A study has been carried out of the sensitization of nitromethane, trinitrotoluene, trinitrobenzene, picric acid and tetryl by the addition of small amounts of amines. The sensitization has been confirmed using dropweight impact experiments and a new method has been found, using differential scanning calorimetry, of making reproducible and quantitative measurements of the effect. It is found that the nitrocompound-amine mixtures decompose at temperatures lower than those of either of the pure components and show a drop in the impact energy required to cause initiation of ignition. The thermal decomposition experiments also yield substantially lower activation energies and an empirical sensitization factor (defined in the text) for nitromethane mixtures that decreases as the nitromethane aci-anion concentration increases. Kinetic deuterium isotope analysis points to C-N bond scission as the rate-determining step in the thermal decomposition of nitromethane and nitromethane-amine mixtures. Laser ionization mass analyses of the solid nitrocompound-amine mixtures indicate significant changes in the fragmentation patterns, with removal of the nitro-group occurring in all cases as the first step in the breakdown of the mixtures, which is not the case for the pure materials. Absorption bands appear in the UV / visible spectra of all the sensitized materials. These bands are ascribed to an intermolecular charge transfer from the nitrogen of an amine group to the antibonding orbital of the nitro-group. It is shown that, with small amounts of amines present, each amine molecule can form a complex with as many nitrocompound molecules as there are amine groups on it. The formation of this charge transfer complex is shown to weaken the nitrocompound C-N bond involved. The weakening of the C-N bond increases directly with increasing binding energy of the complex. Combined with the knowledge that the C-N bond breakage is the rate- ­determining step in the thermal decomposition of these materials and the suggestion that the dominant mechanism in their ignition/detonation is most likely thermal in origin, the sensitization is explained. This explanation deviates from the theories which have been previously proposed.

A comparative study of the structure, energetic performance and stability of nitro-NNO-azoxy substituted explosives

2014 ◽  
Vol 2 (48) ◽  
pp. 20806-20813 ◽  
Author(s):  
Yuan Wang ◽  
Shenghua Li ◽  
Yuchuan Li ◽  
Rubo Zhang ◽  
Dong Wang ◽  
...  
Keyword(s):  
Comparative Study ◽  
Nitro Group ◽  
Detonation Velocity ◽  
Heat Of Formation ◽  
Detonation Pressure ◽  
Unique Structure ◽  
Energetic Performance

Nitro-NNO-azoxy group: the unique structure could improve the density, heat of formation, detonation velocity and detonation pressure of an explosive. Compared with the nitro group, the nitro-NNO-azoxy group has a stronger energetic and electron-attracting property.

An interesting ring cleavage of a 1,2,4-oxadiazole ring

2017 ◽  
Vol 41 (12) ◽  
pp. 4797-4801 ◽  
Author(s):  
Qiong Yu ◽  
Guangbin Cheng ◽  
Xuehai Ju ◽  
Chunxu Lu ◽  
Hongwei Yang
Keyword(s):  
Detonation Velocity ◽  
Ring Opening ◽  
Impact Sensitivity ◽  
Ring Cleavage ◽  
Oxygen Balance ◽  
Zero Density ◽  
Ring Opening Reaction ◽  
Acidic Conditions

Ring-opening reaction: owing to the instability of the 1,2,4-oxadiazole ring under acidic conditions, unexpected compounds 2 and 3 were obtained. Compound 2 exhibits an oxygen balance of zero, density of 1.89 g cm−1 and detonation velocity of 9307 m s−1 as well as impact sensitivity of 20 J.

Crystal structures, thermodynamics and accelerating thermal decomposition of RDX: two new energetic coordination polymers based on a Y-shaped ligand of tris(5-aminotetrazole)triazine

2019 ◽  
Vol 43 (36) ◽  
pp. 14336-14342 ◽  
Author(s):  
Shuo Wu ◽  
Guowei Lin ◽  
Zhengyi Yang ◽  
Qi Yang ◽  
Qing Wei ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Crystal Structures ◽  
Coordination Polymers ◽  
Detonation Velocity ◽  
Hydrothermal Condition ◽  
Detonation Pressure

Two new energetic coordination polymers were prepared under hydrothermal condition. They have good detonation velocity, detonation pressure and effective acceleration effect toward the thermal decomposition of RDX (1,3,5-trinitro-1,3,5-triazinane).

On Elastic-Plastic Explosives for Explosive Hardening

2013 ◽  
Vol 834-836 ◽  
pp. 165-168
Author(s):  
Xiao Yan Hu ◽  
Zhao Wu Shen ◽  
Ying Bin Liu ◽  
Tian Sheng liu
Keyword(s):  
Detonation Velocity ◽  
Production Cost ◽  
Impact Sensitivity ◽  
Detonation Performance ◽  
Hadfield Steel ◽  
Elastic Plastic ◽  
Plastic Explosive ◽  
Plastic Explosives ◽  
The Impact

In order to improve the effect of explosive hardening and reduce the production cost, the elastic-plastic explosive which consists of RDX, rubber, deterrent, antioxidant and plasticizer was prepared. The experiments including density testing, detonation performance, detonation velocity testing, impact sensitivity, and explosive hardening were carried out. The results show that the density of the elastic-plastic explosive is 1.46g/cm3, the detonation velocity is 6670m/s, the impact sensitivity is 28% and the elastic-plastic explosive can be detonated reliably by a detonator. The explosion hardening on Hadfield steel makes the hardness increased from 187HB to 362HB, which increases by 93.5%.

Magnetic, spectral, and thermal behaviour of 2-chloro-4-nitrobenzoates of Co(II), Ni(II), and Cu(II)

2006 ◽  
Vol 60 (3) ◽  
Author(s):  
W. Ferenc ◽  
B. Cristóvão ◽  
B. Mazurek ◽  
J. Sarzyński
Keyword(s):  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Nitro Group ◽  
Magnetic Moment ◽  
Metal Ion ◽  
Water Molecules ◽  
Dehydration Process ◽  
Crystallization Water ◽  
One Step ◽  
Hydrated Complexes

AbstractSome physicochemical properties of 2-chloro-4-nitrobenzoates of Co(II), Ni(II), and Cu(II) were studied. The complexes were obtained as mono-and dihydrates with a metal ion—ligand mole ratio of 1: 2. All complexes are polycrystalline compounds. Their colours depend on the kind of central ion: pink for Co(II) complex, green for Ni(II), and blue for Cu(II) complexes. Their thermal decomposition was studied only in the range of 293 K–523 K because it was found that on heating in air above 523 K 2-chloro-4-nitrobenzoates decompose explosively. Hydrated complexes lose crystallization water molecules in one step. During dehydration process no transformation of the nitro group to nitrito one took place. Their solubilities in water at 293 K are of the orders of 10−3-10−2 mol dm−3. The magnetic moment values of 2-chloro-4-nitrobenzoates determined in the range of 76 K–303 K change from 3.48µB to 3.82µB for Co(II) complex, from 2.24µB to 2.83µB for Ni(II) 2-chloro-4-nitrobenzoate, and from 0.31µB to 1.41µB for Cu(II) complex. 2-Chloro-4-nitrobenzoates of Co(II) and Ni(II) follow the Curie—Weiss law, but the complex of Cu(II) forms dimer.

Applications of Photoelectron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 506-507
Author(s):  
William J. Baxter
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Chemical Composition ◽  
Ultraviolet Radiation ◽  
Thin Layer ◽  
Edge Effects ◽  
Electron Optics ◽  
Surface Layers ◽  
Crystalline Orientation ◽  
Fluorescent Screen

In this form of electron microscopy, photoelectrons emitted from a metal by ultraviolet radiation are accelerated and imaged onto a fluorescent screen by conventional electron optics. image contrast is determined by spatial variations in the intensity of the photoemission. The dominant source of contrast is due to changes in the photoelectric work function, between surfaces of different crystalline orientation, or different chemical composition. Topographical variations produce a relatively weak contrast due to shadowing and edge effects.Since the photoelectrons originate from the surface layers (e.g. ∼5-10 nm for metals), photoelectron microscopy is surface sensitive. Thus to see the microstructure of a metal the thin layer (∼3 nm) of surface oxide must be removed, either by ion bombardment or by thermal decomposition in the vacuum of the microscope.

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