The thermal decomposition of ammonium perchlorate (AP) is considered to be the first step in the combustion of AP-based composite
propellants. In this report, the effect of the specific surface area of titanium oxide (TiO2) catalysts on the thermal decomposition characteristics of AP was examined with a series of thermal analysis experiments.
It was clear that the thermal decomposition temperature of AP decreased when the specific surface area of TiO2 increased. It was also possible that TiO2 influences the frequency factor of AP decomposition because there was no observable effect on the activation energy.
Authors:Zongxue Yu, Yuxi Sun, Wenxian Wei, Lude Lu, and Xin Wang
Orthorhombic structural perovskite NdCrO3 nanocrystals with size of 60 nm were prepared by microemulsion method, and characterized by XRD, TEM, HRTEM, SEM, EDS and
BET. The catalytic effect of the NdCrO3 for thermal decomposition of ammonium perchlorate (AP) was investigated by DSC and TG-MS. The results revealed that the NdCrO3 nanoparticles had effective catalysis on the thermal decomposition of AP. Adding 2% of NdCrO3 nanoparticles to AP decreased the temperature of thermal decomposition by 87° and increased the heat of decomposition from
590 to 1073 J g−1. Gaseous products of thermal decomposition of AP were NH3, H2O, O2, HCl, N2O, NO, NO2 and Cl2. The mechanism of catalytic action was based on the presence of superoxide ion O2− on the surface of NdCrO3, and the difference of thermal decomposition of AP with 2% of NdCrO3 and pure AP was mainly caused by the different extent of oxidation of ammonium.
Isothermal decomposition of orthorhombic ammonium perchlorate (AP) has been studied as a function of concentration of the dopants, SO42− and PO43−. In either case, the rate of decomposition passes through a maximum as the dopant concentration increases. Activation energy of the decomposition process remains unaltered by doping. The results are interpreted in terms of electron transfer mechanism.
Thermal decomposition of -irradiated (dose: 0–3.6 MGy) ammonium perchlorate was followed. The dynamic heating (range: 100–220 °C) and IR spectral measurements were carried out simultaneously. Temperature and dose brought a lowering in peak intensity of NH
ions. Radiolytic products C103 and NH3 are considered to initiate the decomposition process.
Gamma radiation induced decomposition of ammonium perchlorate (AP), pelletized in a KCl/KBr matrix has been followed IR spectrophotometrically. AP absorption peaks decreased in intensity as the -dose increased progressively. Irradiation of powdered AP produces ClO
; its yield increases, attains a maximum and decreases beyond a dose of 0.5 MGy. The result is similar but much slower in the case of -irradiated pellets of pure AP.
Authors:X. Han, Y. Sun, T. Wang, Zh. Lin, Sh. Li, F. Zhao, Z. Liu, J. Yi, and X. Ren
The effects of fullerenes, including fellerene soot (FS), extracted fullerene soot (EFS) and pure C60 on the thermal decomposition of ammonium perchlorate (AP) compared with traditional carbon black (CB) catalyst has been studied
by employing thermogravimetry (TG), differential thermal analysis (DTA), infrared spectroscopy (IR) and ignition temperature
experiments. The results showed that the addition of CB and FS to AP reduced the activation energy as well as the temperature
at maximum decomposition rate, but that of EFS and pure C60 had little effect on the thermal decomposition of AP, and among all catalysts, FS was the best one.
CuO nanocrystals of different surface areas were prepared. All samples were characterized by X-ray diffraction, transition
electron microscope, thermogravimetry, Brunauer-Emmett-Teller technique, Fourier transform infrared spectroscopy, and Raman
spectroscopy. CuO nanocrystals showed a stable monoclinic structure. With increasing surface areas, the surface hydration
became significant, which is followed by shifts in infrared frequencies and Raman phonon modes. CuO nanocrystals were explored
as an additive to catalytic decomposition of ammonium perchlorate (AP). AP decomposition underwent a two-stage process. Addition
of CuO nanocrystals led to a downshift of high-temperature stage towards lower temperatures.
The kinetics of the thermal decomposition of ammonium perchlorate at temperatures between 215 and 260°C is studied, in this
work, by measuring the sample mass loss as a function of time applying the isothermal thermogravimetric method.
From the maximum decomposition rate – temperature dependence two different decomposition stages, corresponding to two different
structural phases of ammonium perchlorate, are identified. For the first region (215–235°C), corresponding to the orthorhombic
phase, the mean value of the activation energy of 146.3 kJ mol–1, and the pre-exponential factor of 3.43⋅1014 min–1 are obtained, whereas for the second region (240–260°C), corresponding to the cubic phase, the mean value of the activation
energy of153.3 kJ mol–1, and the pre-exponential factor of 4.11⋅1014 min–1 are obtained.
This work reported on the thermal decomposition of ammonium perchlorate activated by addition of NiO nanocrystals with different
surface areas. NiO samples were characterized by X-ray diffraction (XRD), transition electron microscope (TEM), Brunauer-Emmett-Teller
(BET) technique, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy. With increasing annealing temperature,
the surface areas of NiO samples reduced from 108.6 to 0.9 m2 g−1. The catalytic activities of NiO nanocrystals on the thermal decomposition of ammonium perchlorate were investigated by thermogravimetric
analysis (TG) coupled with differential thermal analysis (DTA). With addition of NiO nanocrystals, thermal decomposition temperature
of AP decreased greatly. Larger surface areas of NiO nanocrystals promoted the thermal decomposition of AP.
Composite elastomers containing varying amounts of ammonium perchlorate (AP), hydroxyl terminated polybutadiene (HTPB) and toluene-di-isocyanate (TDI) with NCO/OH ratio unity were synthesised by -radiation over a dose range 0–720 kGy. To understand the polymer-filler interactions, stressstrain properties were determined after maintaining the samples at room temperature over 6 months. When progressively increasing either AP content or radiation dose the tensile stress increased and the strain decreased. The additional curing is attributed to the excessive crosslinking brought about by AP in the polymeric matrix.