scholarly journals Evolution of the Micropore Structure of Ammonium Perchlorate during Low-Temperature Decomposition and Its Combustion Characteristics

2021 ◽  
Vol 11 (20) ◽  
pp. 9392
Author(s):  
Haijun Zhang ◽  
Jianxin Nie ◽  
Gangling Jiao ◽  
Xing Xu ◽  
Shi Yan ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Low Temperature ◽  
Ammonium Perchlorate ◽  
Peak Pressure ◽  
Rate Of Change ◽  
Solid Propellants ◽  
Multiple Points ◽  
Temperature Decomposition ◽  
Reaction Intensity ◽  
Almost All

Ammonium perchlorate (AP) is a common oxidant in solid propellants, and its thermal decomposition characteristics at low temperatures (less than 240 °C) are key to the study of the thermal safety of propellants. Here, the low-temperature thermal decomposition characteristics of AP were investigated at 230 °C. The micromorphology of the low-temperature decomposition residues was characterized by scanning electron microscopy and 3D nano-computed tomography in order to analyse the evolution of microscopic pore structures, and the effect of the AP pore structure on combustion performance was then tested and analysed with a homemade closed bomb. The results demonstrate that the low-temperature decomposition of AP first occurs near the surface of the particles, simultaneously starting at multiple points and forming pores, and then gradually expands towards the interior until almost all of the pores connect with one other. Compared with ordinary AP, porous AP has a significantly improved combustion rate. When the ratio of porous AP to Al was 80:20, the peak pressure in the closed bomb was increased by 2.7 times; the rate of change in peak pressure increased 34 times, leading to a higher reaction speed and higher reaction intensity, and a typical explosion reaction occurred.

The low temperature thermal decomposition of ammonium perchlorate: nitryl perchlorate as the reaction intermediate

1984 ◽  
Vol 396 (1811) ◽  
pp. 425-440 ◽  
Keyword(s):  
Thermal Decomposition ◽  
Low Temperature ◽  
Ammonium Perchlorate ◽  
Bond Formation ◽  
Covalent Bond ◽  
Subsequent Reaction ◽  
Temperature Decomposition ◽  
Covalent Bond Formation ◽  
Localized Reaction

We identify nitryl perchlorate as the essential intermediate in the low temperature thermal decomposition of ammonium perchlorate AP. Evidence supporting this identification includes the analytical detection of an oxidized nitrogenous species in partly reacted AP and the ability of ammonium nitrate and several other nitrates to markedly reduce the induction period to decomposition of AP and to accelerate the subsequent reaction. It is also shown that the measured rate of the reaction of pure AP is in very satisfactory agreement with that estimated to result from this amount of NO 2 ClO 4 present. This mechanism differs from those currently accepted, in which the controlling process is believed to involve the transfer of either a proton or an electron. Our proposal is based on the known instability of NO 2 ClO 4 at reaction temperature ( ca . 500 K), the enhanced reactivity compared to the ionic alkali perchlorates being ascribed to covalent bond formation O 2 NO─ClO 3 . Subsequent reactions of the products of breakdown of this species, NO + , ClO 3 - and 2O or O 2 , are regarded as capable of oxidizing reactant NH 4 + (→NO 2 + ), thus regenerating the intermediate. Localized reaction in migrating ‘particles’ of fluid NO 2 ClO 4 , advancing through the reactant and leaving a residue of porous NH 4 ClO 4 , explains the unusual, incomplete low temperature decomposition that is characteristic of AP. The article reports comparative kinetic data for the decomposition of pure AP and the reaction initiated by various added nitrates. Rate studies are complemented by scanning electron microscope examinations of the geometry of interface development and the structure of the decomposed salt. From these and analytical results the role of nitryl perchlorate in AP decomposition is discussed.

scholarly journals HMT-Controlled Synthesis of Mesoporous NiO Hierarchical Nanostructures and Their Catalytic Role towards the Thermal Decomposition of Ammonium Perchlorate

2019 ◽  
Vol 9 (13) ◽  
pp. 2599 ◽  
Author(s):  
Songzhong Ye ◽  
Xiangfeng Guan
Keyword(s):  
Thermal Decomposition ◽  
Ammonium Perchlorate ◽  
Photoelectron Spectroscopy ◽  
Hydrothermal Reaction ◽  
Synthetic Approach ◽  
Hierarchical Nanostructures ◽  
X Ray ◽  
Temperature Decomposition ◽  
Catalytic Role ◽  
Subsequent Calcination

In this work, mesoporous nickel oxide (NiO) hierarchical nanostructures were synthesized by a facile approach by hydrothermal reaction and subsequent calcination. The phase structure, microstructure, element composition, surface area, and pore size distribution of the as-prepared products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and the Brunauer–Emmett–Teller (BET) technique. The precursor of Ni3(NO3)2(OH)4 nanosheet, Ni3(NO3)2(OH)4 microsphere, and Ni(HCO3)2 sub-microsphere was obtained by hydrothermal reaction at 160 °C for 4 h when the ratio of Ni2+/HMT (hexamethylenetetramine) was 2:1, 1:2, and 1:3, respectively. After calcination at 400 °C for 2 h, the precursors were completely transformed to mesoporous NiO hierarchical nanosheet, microsphere, and sub-microsphere. When evaluated as additives of the thermal decomposition of ammonium perchlorate (AP), these NiO nanostructures significantly reduce the decomposition temperature of AP, showing obvious catalytic activity. In particular, NiO sub-microsphere have the best catalytic role, which can reduce the high temperature decomposition (HTD) and low temperature decomposition (LTD) temperature by 75.2 and 19.1 °C, respectively. The synthetic approach can easily control the morphology and pore structure of the NiO nanostructures by adjusting the ratio of Ni2+/HMT in the reactants and subsequent calcination, which avoids using expensive templates or surfactant and could be intended to prepare other transition metal oxide.

Preparation of Carbon-Coated Nano-Fe, Co Particles and their Effects on the Thermal Decomposition of Ammonium Perchlorate

2010 ◽  
Vol 152-153 ◽  
pp. 309-314 ◽  
Author(s):  
Jun Zhao ◽  
Wei Liang Zhou ◽  
Fu Ming Xu
Keyword(s):  
Thermal Decomposition ◽  
Particle Size ◽  
High Temperature ◽  
Ammonium Perchlorate ◽  
Cation Exchange Resin ◽  
Carbon Matrix ◽  
Decomposition Temperature ◽  
Temperature Decomposition ◽  
Carbon Coated ◽  
Size And Morphology

Nano Metal/C (Metal=Fe, Co) composite materials, in which nano iron and cobalt particles were uniformly distributed in carbon matrix, was prepared by pyrolysis of M-exchanged cation exchange resin(M-PAA). X-ray diffraction (XRD), Transmission Electron Microscope (TEM) results showed the particle size and morphology of nano iron and cobalt in M/C could be controlled by pyrolytic temperature. The particle size of Co and Fe in M/C obtained at 500 was respectively 15-40 nm and 10-35 nm. DTA was employed to test the thermal decomposition of ammonium perchlorate (AP) in the M/C and AP mixture. Results indicated the decomposition temperature at high-temperature decomposition of AP was lowered with the addition of amount of M/C-500, and the high temperature decomposition peaks of AP respectively lowered as much as 145.2°Cand 68.3°C with adding amount of 5% of Co/C and Fe/C obtained at 500 . The high and low temperature decomposition peaks of AP overlapped with addition of Co/C.

Influence of the electric field on the low-temperature thermal decomposition of ammonium perchlorate/polystyrene propellant

1982 ◽  
Vol 46 ◽  
pp. 1-6 ◽  
Author(s):  
K. Kishore ◽  
V.R. Pai Verneker ◽  
M.R. Sunitha
Keyword(s):  
Thermal Decomposition ◽  
Low Temperature ◽  
Electric Field ◽  
Ammonium Perchlorate

Oxygen vacancy enriched Cu-WO3 hierarchical structure for thermal decomposition of ammonium perchlorate

2021 ◽  
Author(s):  
Jing Shi ◽  
Xiangying Xing ◽  
Huixiang Wang ◽  
Lin Ge ◽  
Haizhen Sun ◽  
...  
Keyword(s):  
Thermal Decomposition ◽  
Oxygen Vacancy ◽  
Ammonium Perchlorate ◽  
Hierarchical Structure ◽  
Solid Propellants ◽  
Composite Solid Propellants ◽  
Composite Solid

The design and fabrication of efficient catalysts for ammonium perchlorate (AP) decomposition is crucial to the performance of composite solid propellants. Herein, a novel hierarchical structure material of Cu-WO3 nanowire...

The thermal decomposition of ammonium perchlorate at low temperature

1967 ◽  
Vol 29 (11) ◽  
pp. 2723-2730 ◽  
Author(s):  
V.R. Pai Verneker ◽  
J.N. Maycock
Keyword(s):  
Thermal Decomposition ◽  
Low Temperature ◽  
Ammonium Perchlorate
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