Mixture Of Ammonium Perchlorate Research Articles

Construction of Hydrophobic Ammonium Perchlorate with Synergistic Catalytic Effect Based on Supramolecular Self-Assembly for Synchronously Catalyzing the Thermal Decomposition of Ammonium Perchlorate and the Combustion of Aluminum.

Ammonium perchlorate (AP), as an important additive component of composite propellants, is critical to the combustion performance of propellants. Herein, AP@1H,1H,2H,2H-perfluorodecyltrichlorosilane (AP@PF) was prepared by establishing a tannic acid-iron ion (TA-Fe) supramolecular self-assembly layer on the AP surface and connecting the 1H,1H,2H,2H-perfluorodecyltrichlorosilane interfacial layer. Results demonstrate that TA-Fe and 1H,1H,2H,2H-perfluorodecyltrichlorosilane are uniformly bound to the surface layer of AP. AP@PF has a lower high-temperature thermal decomposition peak compared to AP. Meanwhile, the exothermic values of low-temperature thermal decomposition (338 J/g) and high-temperature thermal decomposition (597 J/g) of AP@PF are significantly higher than those of AP. In addition, AP@PF exhibits different surface interfacial properties, such as floating on the water surface and exhibiting a static contact angle of 105° on water. AP@PF shows almost no moisture absorption after aging in humid air for 30 days. The exothermic value of the mixture of AP@PF and aluminum powder (156 J/g) is significantly higher than that of the mixture of AP and aluminum (54 J/g), and the mixture of AP@PF and aluminum powder exhibits a higher calorific value and a stronger emission spectrum. Finally, the synergistic catalytic mechanism of AP@PF on the thermal decomposition of AP and the combustion of aluminum powder is also discussed.

Catalytic thermal decomposition of ammonium perchlorate by a series of lanthanide EMOFs

Given their unique and excellent properties, metal–organic frameworks (MOFs) materials have been used in many scientific fields. EMOFs use energetic materials as ligands, which can provide part of the energy for the system while catalyzing ammonium perchlorate. The energetic material 1.1′-dihydroxyazotetrazole (H2AzTO), as a high-energy nitrogen-rich material, was selected as a ligand. Five kinds of La3+, Ce3+, Pr3+, Nd3+, and Sm3+ lanthanide EMOFs were synthesized and obtained. Single crystal X-ray diffraction tests were conducted to obtain the crystal structures of EMOFs 1–5, which indicate that they have similar crystal structures. The thermal stabilities of EMOFs 1–5, which are obtained by differential scanning calorimetry (DSC) tests, are improved compared with that of the ligand. The results of thermic-decomposition of ammonium perchlorate (AP) and AP mixtures with 10 wt% EMOFs 1–5 show that except for AP mixed with 10 wt% compound 2, the high-temperature decomposition peak temperature of AP mixed with other compounds is significantly advanced (up to 59.3–88.3 K), and the decomposition of AP is continuous and violent. EMOFs 3–5 have good application prospects for the catalytic thermic-decomposition of AP.

Detonation properties of explosive proppants based on slurry nitromethane plus ammonium perchlorate mixtures

In this paper, the results of investigation on detonation properties of heterogeneous mixtures of ceramic proppants with slurry liquid explosives (LE) such as nitromethane (NM) plus ammonium perchlorate compositions are presented. The mixtures discussed are promised to be used for far field fracture stimulation of oil bearing formation subjected to hydraulic fracturing. Experimental results on detonation velocities of LE-proppant mixtures in long tubes up to 25 diameters versus internal diameters are presented. Results of experimental comparison of detonability of LE studied with pure NM in proppant matrix are also represented. The objective of the study was to assess detonability and detonation parameters of these mixtures at various initial conditions.

Transition of Convective Combustion into Low-Velocity Detonation in a Low Porous Stochiometric Mixture of Ammonium Perchlorate with Polymethyl Methacrylate in a Device with Mass Ejection

Transition of Convective Combustion into Low-Velocity Detonation in a Low Porous Stochiometric Mixture of Ammonium Perchlorate with Polymethyl Methacrylate in a Device with Mass Ejection

Specific Features of the Initiation and Propagation of Low-Velocity Detonation in the High-Density Charges Based on Ammonium Perchlorate Mixtures with Combustible Additives

The propagation features and critical conditions of low-velocity detonation (LVD) in the high-density charges of finely dispersed ammonium perchlorate (APC) mixtures with combustible and explosive additives are studied. The effect of the relative charge density, the combustible component type, and the ratio of mixture components, including the mixtures strongly enriched with a combustible agent, on the propagation of detonation is considered. It is shown that the dependence of the detonation velocity on the relative charge density in the case of APC mixtures with combustible additives has a plateau-like region, in which the detonation velocity is at a level of 2000 m/s and is practically independent of the density and nature of the combustible component. Moreover, the critical charge density, above which the failure of LVD is observed, is revealed. In the case of ternary mixtures with a liquid explosive (nitromethane) additive, there is no similar dependence, and the detonation velocity monotonically grows with an increase in the relative density. The critical initiation pressures of compositions are also determined within the density range, where the density has no effect on the detonation velocity. The performed studies make it possible to refine the composition and characteristics of high-density mixtures, for which the application of LVD regimes can ensure the creation of efficient explosion-proof impulse devices.

Thermochemical and Energy Characteristics of Symmetric Nitro and Azido Derivatives of Diazen-Ter-Furazans

The heat of combustion and enthalpy of formation of bis(4 $$''$$ -nitro[3,3 $$'$$ :4 $$'$$ ,3 $$''$$ ]terfurazan-4-yl)-diazene (DNFNF) and (bis(4 $$''$$ -azido-[3,3 $$'$$ :4 $$'$$ ,3 $$''$$ ]terfurazan-4-yl)-diazene (DAzFNF) were first experimentally determined. It is found that the energy increment for replacing the nitro group with an azide group in the furazan cycle averages 290 kJ/mol and is close to the increment for replacing NO2 with N3 in trinitroethane. The dependence of the energy parameters of metal-free rocket propellants based on a mixture of ammonium perchlorate and DNFNF or DAzFNF with an active binder on the content of the high-enthalpy component in the formulation was studied by thermodynamic analysis.

Theoretical investigation on the interaction mechanism of FOX-7/AP mixed crystals

ABSTRACTHerein, in order to determine the formation feasibility of 1,1-diamino-2,2-dinitroethylene (FOX-7)/ ammonium perchlorate (AP) mixed crystals, three configurations of FOX-7/AP composites (FOX-7/AP1, FOX-7/AP2, FOX-7/AP3) were optimised, and the structures of FOX-7/AP mixed crystals were constructed. Then the electrostatic potential, binding energy and electronic density topology of FOX-7/AP composites were calculated by using the density functional theory. Finally, the radial distribution function between H atoms and O atoms of FOX-7/AP mixtures was calculated through molecular dynamics. As demonstrated by the results, there are hydrogen bond interactions in three configurations of FOX-7/AP composites. The interaction energies of FOX-7/AP1, FOX-7/AP2 and FOX-7/AP3 are 8.396, 20.537 and 38.189 kJ▪mol−1, respectively. The order of the electron density ρ(r) at the bond critical point (BCP) of three FOX-7/AP composites is FOX7-AP3 > FOX7-AP2 > FOX7-AP1. There are apparent peaks at the range of 0.11–0.31 nm and 0.31–0.5 nm for FOX-7(10-1)/AP, FOX-7(011)/AP, FOX-7(101)/AP mixed crystals. The interaction strength of the hydrogen bond is greater than that of strong van der Waals force. Therefore, it is feasible to combine FOX-7 with AP to form mixed crystals. As the content of AP in the mixed crystal is on the rise, the oxygen balance of the system shows a gradually increasing trend.

Behavior of Low-Velocity Detonation in Stoichiometric Mixture of Ammonium Perchlorate and Polymethyl Methacrylate

Low-velocity detonation in mixtures of ammonium perchlorate and fuel additives in high relative density charges is an interesting subject for the scientific research, with potential for practical applications in pulse nozzle and projective setups. However, information about the process is scanty and mainly concerns the measurements of the wave propagation velocities. This paper describes the results of a research aimed at obtaining the data base on properties and behavior of low-velocity detonation (LVD) in pressed charges of the mixture of ammonium perchlorate and 15% polymethyl methacrylate. The firings have been fulfilled at the pulse laboratory projectile setup and the strong steel confinements equipped with the nozzle block or a projectile with the process initiated by a booster produced from RDX or the TNT/RDX 30/70 mixture. The thrust impulse, trajectory of the projectile, pressure, and LVD wave front trajectory have been recorded. According to the measurement results, the muzzle velocity, the pressure at the projectile, and the burning completeness of the mixture have been calculated. In the experiments, the relative charge density has varied from 0.85 to 0.96, the ammonium perchlorate particle size has been from 20 to 200 μm, and the charge length and the projectile mass have varied as well. The experiments were supplemented with numerical simulation. Emphasis was lain on the interaction of a low-velocity detonation wave with end rarefaction waves. The conditions under which the high completeness of chemical conversion of the mixture can be reached with the acceptable level of the maximum pressure (1–1.5 GPa) are considered.

Synthesis of Energetic Complexes [Co(en)(H2BTI)2]2 ⋅ en, [Cu2(en)2(HBTI)2]2 and Catalytic Study on Thermal Decomposition of Ammonium Perchlorate

AbstractA nitrogen‐rich compound 4,5‐bis(1H‐tetrazol‐5‐yl)‐1H‐imidazole (H3BTI) with high energy density has been reported as ligand to make metal‐organic energetic catalysts to improve the energy of catalysts for the first time. The high energetic catalysts [Co(en)(H2BTI)2]2 ⋅ en and [Cu2(en)2(HBTI)2]2 were successfully synthesized and the structures of the complexes were confirmed by X‐ray single‐crystal diffraction. The catalytic effects of complexes on the thermal decomposition of ammonium perchlorate (AP) have been investigated separately by differential scanning calorimetry (DSC). The DSC results show that the AP can be completely decomposed at the temperature of 333.7 °C and 336.1 °C, respectively, which indicates that the pristine “two‐step” thermal decomposition of AP was transformed to a “one step” route upon addition of the copper catalysts. Besides the excellent catalytic performance of AP decomposition, the high energetic ligand HnBTI can also release a large number of heats in the decomposition process, which can significantly enhance the total released heat of the mixture of AP.

Studies on the Thermal Behaviors of Hexogen, Ammonium Perchlorate and Their Mixtures by TG-DSC

In order to study the effect of the oxidizer ammonium perchlorate (AP) on the energy release of composite energetic materials, the thermal decomposition of AP with different particle size, Hexogen (RDX), and their mixtures were studied by means of thermogravimetry-differential scanning calorimetry (TG-DSC). The results showed that RDX had one weight loss step and there were two weight loss steps for AP and the mixture of AP and RDX. We can also conclude that RDX and AP accelerate the thermal decomposition of each other and the change of particle size of AP has no effect on this acceleration.

$$\textit{Ex}\,\textit{situ}$$ Ex situ synthesis of G/ $$\upalpha $$ α - $$\hbox {Fe}_{2}\hbox {O}_{3}$$ Fe 2 O 3 nanocomposite and its catalytic effect on the thermal decomposition of ammonium perchlorate

$$\upalpha $$ - $$\hbox {Fe}_{2}\hbox {O}_{3}$$ nanoparticles were prepared by a facile hydrothermal method using ferric chloride hexahydrate ( $$\hbox {FeCl}_{3}{\cdot }$$ 6H $$_{2}\hbox {O}$$ ) as a precursor. Graphene oxide (GO) was synthesized using a modified Hummers method and graphene nanosheets (G) were successfully obtained by thermal reduction of GO. G/ $$\upalpha $$ - $$\hbox {Fe}_{2}\hbox {O}_{3}$$ nanocomposite was prepared using ex situ synthesis in the presence of $$\upalpha $$ - $$\hbox {Fe}_{2}\hbox {O}_{3}$$ nanoparticles and GO solution. The characterization of the as-prepared materials was performed using X-ray diffraction analyses and Fourier transform infrared spectroscopy; their morphology was investigated by scanning electron microscopy and transmission electron microscopy; the specific surface area ( $$S_{\mathrm{BET}}$$ ) was determined by nitrogen adsorption; their catalytic activity on the thermal decomposition of ammonium perchlorate (AP) was investigated by differential thermal analysis (DTA). The results of DTA indicated that the obtained nanomaterials contribute in ameliorating the thermal decomposition of AP; specifically, the high decomposition temperature of AP decreases from 432 to 380 $$^{\circ }$$ C. A significant decrease in the activation energy was also achieved in the presence of these nanomaterials, and the mixture of ammonium perchlorate with G/ $$\upalpha $$ - $$\hbox {Fe}_{2}\hbox {O}_{3}$$ showed the lowest value (from 129 to $$80.33\,\hbox {kJ}\,\hbox {mol}^{-1}$$ ). Graphene (G), $$\upalpha $$ - $$\hbox {Fe}_{2}\hbox {O}_{3}$$ nanoparticles and G/ $$\upalpha $$ - $$\hbox {Fe}_{2}\hbox {O}_{3}$$ nanocomposite are successfully obtained using a simple hydrothermal method. The results of DTA show that the G/ $$\upalpha $$ - $$\hbox {Fe}_{2}\hbox {O}_{3}$$ nanocomposite displays the best catalytic activity in enhancing the thermal decomposition of ammonium perchlorate by reducing its HTD from 432 $$^{\circ }$$ C to 380 $$^{\circ }$$ C.

Detonation Velocity of Mechanically Activated Mixtures of Ammonium Perchlorate and Aluminum

Detonation Velocity of Mechanically Activated Mixtures of Ammonium Perchlorate and Aluminum

Investigation of Blast Performance and Solid Residues for Layered Thermobaric Charges

AbstractThe confined explosion of an annular layered charge composed of a phlegmatized RDX (RDXph) core and an external layer consisting of aluminum powder (Al) or a mixture of ammonium perchlorate (AP) and Al was studied. Experiments were carried out in fully and partially closed structures, i.e., in the explosion chamber of 150 dm3 in volume and in the 40 m3 volume bunker with four small holes and a doorway. Two types of aluminum powder were used in the mixtures. Signals of overpressure from two piezoelectric gauges located at the chamber wall were recorded and the influence of aluminum contents and particle size on a quasi‐static pressure (QSP) was studied. Moreover, the solid residues from the chamber were analyzed by using SEM, TG/DTA and XRD techniques to determine their structure and composition. Pressure and light histories recorded in the bunker enable us to determine the blast wave characteristics and time‐duration of light output. The effect of the charge mass and aluminum particle size on blast wave parameters were investigated. For comparison, the test for RDXph and TNT charges were also carried out.

On convective combustion of ammonium perchlorate mixtures with aluminum

This paper presents an experimental study of the effect of aluminum particle shape, sample density, and small additions of an organic fuel (polymethylmethacrylate) on the initiation and development of convective combustion in bulk and pressed mixtures of ammonium perchlorate with aluminum. It is shown that replacing spherical particles of ASD-4 aluminum by flaky particles of PAP-2 and increasing the mixture density above a certain value results in an increase in the minimum length of samples at which convective combustion begins and its transition to an explosive process is recorded. With the addition of small amounts (up to 4%) of polymethylmethacrylate, this length decreases.

Characteristics of the underwater explosion of a nonideally detonating aluminum-rich energetic material

An experimental study of the characteristics of the explosion of mixtures of ammonium perchlorate, aluminum, and nitromethane with a large excess of aluminum (1.45 to 1.66 g/cm3 in density) confined in plastic enclosures and immersed in small elastic-wall reservoirs with water is conducted. It is shown that composite charges, 20 mm in diameter, surrounded by a water layer of thickness 20–30 cm and detonate in a nonideal detonation mode. High-speed cinematography records show the possibility of the intense mixing of the detonation products with the surrounding water and of the burning of excess aluminum particles in a heterogeneous cloud. The time scales of the development of secondary energy release by burning of aluminum particles in water are estimated. The possibility of controlling the characteristics of the pressure waves generated by the explosion, for example, by means of a preliminary bubbling of the water with air near the charge, is demonstrated.

Onset and development of convective burning in highly porous charges of ammonium perchlorate and its mixtures with aluminum

The onset and development of convective burning in the charges with a high porosity prepared from the finely dispersed ammonium perchlorate and its mixtures with aluminum ASD-4 is studied. The experiments were carried out in a constant volume bomb with the record of the pressure-time history and in the confinement with a slit, which makes it possible to perform simultaneously the photographic and piezometric recording of the process. Special attention is given to the mixtures with the increased aluminum content. The minimum lengths of samples are determined at which convective burning or explosion occur. The dependence of these lengths on the aluminum concentration in the mixture is determined. The possibility of convective burning and low-velocity detonation in ammonium perchlorate without the combustible additive is shown. It is established that the introduction of aluminum causes the ignition of the dispersed suspension behind the front of convective burning with the formation of the brightly glowing high-pressure zone (the secondary wave), which intensively expands in both sides from the place of origin. When the secondary wave overtakes the front of convective burning, the low-velocity detonation appears. The obtained results are of interest for explosion safety of the mixtures of ammonium perchlorate with aluminum and for designing generators of high-temperature suspensions with aluminum particles.

Self-assembled CuO nanoarchitectures and their catalytic activity in the thermal decomposition of ammonium perchlorate

CuO shuttle-like and flower-like nanocrystals were synthesized through a one-step, low-temperature solution-phase method in the presence of a cation surfactant, hexadecyl trimethyl ammonium bromide. These nanocrystals were studied as an additive for promoting the thermal decomposition of ammonium perchlorate (AP). With the addition of CuO shuttle-like and flower-like nanocrystals, the thermal decomposition temperature of AP decreased. The structure, particle size, and morphology of resulting CuO powders were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Thermogravimetric analysis technique was applied to investigate the thermal decomposition of mixtures of AP and as-prepared CuO nanocrystals.

Size effect in laser-induced initiation of a pyrotechnical composition (ammonium perchlorate and ultrafine aluminum)

The energy thresholds and ignition delays of pressed samples of a stoichiometric pyrotechnical mixture of ammonium perchlorate and ultrafine aluminum are studied as functions of the diameter of the laser spot created by a millisecond laser pulse. A clearly expressed size effect is found. A characteristic size determining the boundary between the wide and narrow beams of the laser pulse applied is determined. The influence of optical properties of the examined composition on the behavior of the size dependences is discussed. The relation between the nature of the size effect and the laws of light scattering in the volume of powdered pyrotechnical mixtures is considered.

Radiative Ignition of Fine‐Ammonium Perchlorate Composite Propellants

AbstractRadiative ignition of quasi‐homogeneous mixtures of ammonium perchlorate (AP) and hydroxyterminated polybutadiene (HTPB) binder has been investigated experimentally. Solid propellants consisting of fine AP (2 μm) and HTPB binder (~ 76/24% by mass) were ignited by CO2 laser radiation. The lower boundary of a go/no‐go ignition map (minimum ignition time vs. heat flux) was obtained. Opacity was varied by adding carbon black up to 1% by mass. Ignition times ranged from 0.78 s to 0.076 s for incident fluxes ranging from 60 W/cm2 to 400 W/cm2. It was found that AP and HTPB are sufficiently strongly absorbing of 10.6 μm CO2 laser radiation (absorption coefficient ≈250 cm−1) so that the addition of carbon black in amounts typical of catalysts or opacitymodifying agents (up to 1%) would have only a small influence on radiative ignition times at 10.6 μm. A simple theoretical analysis indicated that the ignition time‐flux data are consistent with in‐depth absorption effects. Furthermore, this analysis showed that the assumption of surface absorption is not appropriate, even for this relatively opaque system. For broadband visible/near‐infrared radiation, such as from burning metal/oxide particle systems, the effects of in‐depth absorption would probably be even stronger.

A Mixture of Ammonium Perchlorate and Sodium Chlorate Enhances Alterations of the Pitutary-Thyroid Axis Caused by the Individual Chemicals in Adult Male F344 Rats

Ammonium perchlorate (AP) and sodium chlorate (SC) have been detected in public drinking water supplies in many parts of the United States. These chemicals cause perturbations in pituitary-thyroid homeostasis in animals by competitively inhibiting iodide uptake, thus hindering the synthesis of thyroglobulin and reducing circulating T(4) (thyroxine). Little is known about the short-term exposure effects of mixtures of perchlorate and chlorate. The present study investigated the potential for the response to a mixture of these chemicals on the pituitary-thyroid axis in rats to be greater than that induced by the individual chemicals. Adult male F-344 rats were exposed, via their drinking water, to the nominal concentrations of 0.1, 1.0, 10 mg/L AP or 10, 100, 1000 mg/L SC and their mixtures for 7 days. Serum T(4) levels were significantly (p < 0.05) reduced in rats following exposure to the mixtures, but not after exposure to the individual chemicals. Serum T(3) (triiodothyronine) was not altered by treatment and TSH (thyroid stimulating hormone) was only increased after the high-dose chlorate treatment. Histological examination of the thyroid gland showed colloid depletion and hypertrophy of follicular epithelial cells in high-dose single chemical and all mixture-treated rats, while hyperplasia was observed only in some of the rats treated with mixtures (AP 10 + SC 100, AP 0.1 + SC 1000, and AP 10 + SC 1000 mg/L). These data suggest that short-term exposure to the mixture of AP and SC enhances the effect of either chemical alone on the pituitary-thyroid axis in rats.