Thermal decomposition of ammonium perchlorate

Dynamic response of laminated composite plates under initial stress

The influence of Co-60 gamma-irradiation, up to 500 Mrad, on the kinetics of the thermal decomposition of lithium perchlorate has been studied over the temperature range 400–440°C. The material (m.p. 236°C) decomposes in the molten state and the lithium chloride formed remains dissolved initially but separates out as solid after about 50% decomposition. Decomposition occurs in four stages, viz., (i) initial gas evolution, (ii) induction, (iii) acceleratory and (iv) decay. Kinetic analysis of stages (i) and (ii) could not be made with any degree of certainty. The acceleratory and decay stages analyse according to the Prout-Tompkins relationship, first order law, and the contracting volume formula with two constants in each case, one for the acceleratory and the other for the decay stage. Activation energies for these two stages calculated from the Prout-Tompkins constants are 64.1 and 33.3 kcal mole−1 respectively. Irradiation increases initial gas evolution and shortens the induction period. It a...

Influence of irradiation on the thermal decomposition of lithium perchlorate

Thin films of ammonium perchlorate (NH4ClO4) were exposed to energetic electrons at 5.5 K to explore the radiolytic decomposition mechanisms. The effects of radiolysis were monitored on line and in situ via Fourier transform infrared spectroscopy (FTIR) in the condensed phase along with electron impact ionization quadrupole mass spectrometry (EI-QMS) and single-photon photoionization reflectron time-of-flight mass spectrometry (PI-ReTOF-MS) during the temperature-programmed desorption (TPD) phase to probe the subliming molecules. Three classes of molecules were observed: (i) nitrogen bearing species [ammonia (NH3), hydroxylamine (NH2OH), molecular nitrogen (N2), nitrogen dioxide (NO2)], (ii) chlorine carrying molecules [chlorine monoxide (ClO), chlorine dioxide (ClO2), dichlorine trioxide (Cl2O3)], and (iii) molecular oxygen (O2). Decay profiles of the reactants along with the growth profiles of the products as derived from the infrared data were fit kinetically to obtain a reaction mechanism with the ini...

Electron Radiolysis of Ammonium Perchlorate: A Reflectron Time-of-Flight Mass Spectrometric Study

Influence of irradiation on the thermal decomposition of some perchlorates

The thermal decomposition kinetics have been determined for ammonium perchlorate crystals subjected to a fast neutron irradiation or to a fast neutron irradiation followed by a gamma‐ray irradiation. Qualitatively, the radiation induced changes are similar to those obtained in this and in previous studies, with samples exposed only to gamma rays. The induction period is shortened and the rate constants, obtained from an Avrami‐Erofeyev kinetic analysis, are modified. The acceleratory period constant increases and the decay period constant decreases. When compared on an equal deposited energy basis, the fast neutron induced changes are appreciably larger than the gamma‐ray induced changes. Some, or all, of the fast neutron induced effects might be attributable to the introduction of localized regions of concentrated radiation damage (``spikes'') by lattice atom recoils which become thermal decomposition sites when the crystals are heated.

Effect of fast neutron, gamma‐ray, and combined radiations on the thermal decomposition of ammonium perchlorate single crystals

The thermal decomposition kinetics of irradiated and unirradiated ammonium perchlorate and ammonium perchlorate powder-aluminum particle mixtures has been studied by determining decomposition gas pressurevs. heating time with samples at a controlled temperature Qualitatively the radiation induced changes are similar to those obtained in previous studies on ‘pure’ ammonium perchlorate. The induction period is shortened and the acceleratory and decay period rate constants are increased. The data have been analyzed using Avrami-Erofeev kinetics. The results for pure unirradiated material are in accord with published results. The activation energies for the induction, acceleratory and decay periods for pure pellets were found to be 133.5±6.7, 131.8±6.7 and 127.2±6.7 kJ·mol, respectively. Samples were exposed to either a single gamma-ray irradiation, fission neutron irradiation followed by a gamma-ray irradiation, or to a proton irradiation. When compared on an equal energy deposited basis, the fast neutron induced changes are appreciably larger than the gamma-ray changes. However, the proton induced changes are comparable or slightly more than the gamma-ray effects. Some, or all, of the fast neutron effects can be attributable to the concentrated radiation damage ‘spikes’ along the path of lattice atom recoils. It is likely that these become thermal decomposition sites when the crystals are heated. Protons create fewer spikes than fast neutrons. Overall, the results indicate that any ammonium perchlorate-aluminum propellant mixtures that may be exposed to radiation environments, such as used in this study, should be subjected to a thorough radiation effects analysis if reliable performance is required.

C. S. Wang

Papers

Effect of fast neutron, gamma‐ray, and combined radiations on the thermal decomposition of ammonium perchlorate single crystals

The effects of fast neutron, gamma-ray and combined radiations on the thermal decomposition of ammonium perchlorate powder-aluminum particle mixtures