Decomposition of ammonium perchlorate

Factors which Catalyze the Decomposition of Ammonium Perchlorate. Irradiation of AP with X-rays or gamma radiation causes it to decomp at a lower temp, presumably by the formn of holes or active sites in the cryst (Ref 36). Metal salts have been found to lower the decompn point of AP by as much as 80° (Ref 39), and to lower the induction period for its expln at 233° by 21 minutes (Ref 41). Inorg salts which have been found to catalyze the decompn of AP are listed below ... 

Adiabatic Decomposition of Ammonium Perchlorate , SRI Report PU-3573 (1965), AD 640084 33) M.L. Essick, Literature Search. ... 

The Thermal Decomposition of Ammonium Perchlorate — A Literature Review , U of Miami. Dept of Chem Special Report 6 (1968), AD 673542 43) O, Svejka, CzechP 129074... 

Heath and Majer (H3) have recently used a mass spectrometer to study the decomposition of ammonium perchlorate. Decomposition was detected in the range from 110° to 120°C. At this temperature, there were ions in the mass spectrum caused by NH3, HC104, Cl2, HC1, nitrogen oxides, and 02. The appearance of the species NO, N02,02, and Cl2 in the decomposition products under very low pressure (i.e., in the absence of gas-phase molecular collisions) indicates that the principal decomposition reactions take place in the crystal and not in the gas phase. 

Catalysts which enhance the burning rate of composite propellants are generally believed to accelerate the decomposition of ammonium perchlorate, but the catalytic mechanism is still not very clear. The important observed aspects of this catalysis can be summarized as follows ... 

Horton (H9, H10) has obtained additional acoustic-admittance data for a series of composite propellants. At a given frequency, decreasing the mean oxidizer particle size increases the acoustic admittance and thereby the tendency for instability. Horton also investigated the effects on the acoustic admittance of the incorporation of traces of copper chromite, a known catalyst, for the decomposition of ammonium perchlorate, lithium fluoride (a burning-rate depressant), and changes in binder these data are difficult to analyze because of experimental errors. 

Accumulatory pressure measurements have been used to study the kinetics of more complicated reactions. In the low temperature decomposition of ammonium perchlorate, the rate measurements depend on the constancy of composition of the non-condensable components of the product mixture [120], The kinetics of the high temperature decomposition [ 59] of this compound have been studied by accumulatory pressure measurements in the presence of an inert gas to suppress sublimation of the solid reactant. Reversible dissociations are not, however, appropriately studied in a closed system, where product readsorption and diffusion effects within the product layer may control, or exert perceptible influence on, the rate of gas release [121]. 

Some limitations of optical microscopy were apparent in applying [247—249] the technique to supplement kinetic investigations of the low temperature decomposition of ammonium perchlorate (AP), a particularly extensively studied solid phase rate process [59]. The porous residue is opaque. Scanning electron microscopy showed that decomposition was initiated at active sites scattered across surfaces and reaction resulted in the formation of square holes on m-faces and rhombic holes on c-faces. These sites of nucleation were identified [211] as points of intersection of line dislocations with an external boundary face and the kinetic implications of the observed mode of nucleation and growth have been discussed [211]. 

Although it would appear that plots of ln[—ln(l — a)] against ln(f — t0) provide the most direct method for the determination of n from experimental a—time data, in practice this approach is notoriously insensitive and errors in t0 exert an important control over the apparent magnitude of n. An alternative possibility is to compare linearity of plots of [—ln(l — a)]1/n against t this has been successful in the kinetic analysis of the decomposition of ammonium perchlorate [268]. Another possibility is through the use of the differential form of eqn. (6)... 

The Avrami—Erofe ev equation, eqn. (6), has been successfully used in kinetic analyses of many solid phase decomposition reactions examples are given in Chaps. 4 and 5. For no substance, however, has this expression been more comprehensively applied than in the decomposition of ammonium perchlorate. The value of n for the low temperature reaction of large crystals [268] is reduced at a 0.2 from 4 to 3, corresponding to the completion of nucleation. More recently, the same rate process has been the subject of a particularly detailed and rigorous re-analysis by Jacobs and Ng [452] who used a computer to optimize curve fitting. The main reaction (0.01 < a < 1.0) was well described by the exact Avrami equation, eqn. (4), and kinetic interpretation also included an examination of the rates of development and of multiplication of nuclei during the induction period (a < 0.01). The complete kinetic expressions required to describe quantitatively the overall reaction required a total of ten parameters. 

Fig. 16. Graphical representation of Arrhenius parameters for the low temperature decomposition of ammonium perchlorate (pelleted, orthorhombic, o, and cubic, , forms). Compensation behaviour is observed. Data from Jacobs and Ng [452]. N = nucleation, B = branching, G = growth processes.

Fig. 17. Unified reaction scheme for the thermal decomposition of ammonium perchlorate, proposed by Jacobs et al. [59,925,926], In the low temperature reaction, the interaction occurs between adsorbed species (a) whereas the high temperature reaction and sublimation process involved volatilization intermediates (g). X] and X2 represent mixtures of intermediates.

In a review of the course and mechanism of the catalytic decomposition of ammonium perchlorate, the considerable effects of metal oxides in reducing the explosion temperature of the salt are described [1], Solymosi s previous work had shown reductions from 440° to about 270° by dichromium trioxide, to 260° by 10 mol% of cadmium oxide and to 200°C by 0.2% of zinc oxide. The effect of various concentrations of copper chromite , copper oxide, iron oxide and potassium permanganate on the catalysed combustion of the propellant salt was studied [2], Similar studies on the effects of compounds of 11 metals and potassium dichromate in particular, have been reported [3], Presence of calcium carbonate or calcium oxide has a stabilising effect on the salt, either alone or in admixture with polystyrene [4],... 

A study of the kinetics of the decomposition of ammonium perchlorate has been made by Bircumshaw and Newman [5]. The gaseous products, up to a temperature of 300°C, were found to be oxygen, chlorine, chlorine dioxide, nitrous oxide, nitrogen tetroxide, chlorine dioxide, hydrochloric acid, perchloric acid and water. The total volume of oxygen and nitrogen produced by unit weight of the solid showed practically no variation up to about 300°C. 

Fig. 176. Rate of decomposition of ammonium perchlorate. Variation with temperature according to Bircumshaw and Newman [5],...

The recent experiments by Galwey and Jacobs [7a] were mainly dedicated to examining the thermal decomposition of ammonium perchlorate above ca. 350°C. They found the decomposition differs in several respects from that below this temperature, complete decomposition occurs, whereas at low temperatures a residue of ammonium perchlorate always remains as described above. 

According to Glasner and Makovky [13] the activation energy of decomposition of ammonium perchlorate is 31.0 kcal/mole in the temperature range 440-478°C. 

The introduction of silver ions which act as electron traps enhances the radiation-induced changes in the thermal decomposition of ammonium perchlorate. Irradiated samples containing silver show thermal decomposition similar to samples without silver, but which received a considerably greater radiation dose. 

The same authors [7b] examined the thermal decomposition of ammonium perchlorate with charcoal (see also Vol. III). At temperatures below 240°C the... 

Explosive decomposition of ammonium perchlorate was estimated by Naoum and Aufschlager [14] to proceed according to the equation ... 

Oxygen Taliani Test of Gamma-Irradiated Propellants ARP, AHH, and CDT , NPP-TMR-172, Naval Propint Plant, Indian Head (1959) 78) E.S. Freeman et al, The Effects of X-Ray and Gamma Ray Irradiation on the Thermal Decomposition of Ammonium Perchlorate in the Solid State , JPhysChem 64, 1727 (1960) also PATR 2673 (1960) 79) G. Todd E. Parry,... 

Herley et al, Effect of Fast Neutron, Gamma-ray and Combined Radiations on the Thermal Decomposition of Ammonium Perchlorate Single Crystals , JChemPhys 60, 2340 (1974)... 

Herley et al, Recent Radiation Effect Studies on Ammonium Perchlorate. Part II The Effect of Fast Neutron, Gamma Ray and Combined Radiation on the Thermal Decompositions of- Ammonium Perchlorate Powder—Aluminum Particle Mixtures , Ibid, paper 2.2b, pp 301—15 (1975) 242) W.D. Hutchinson, Neutron Effects on Solid Propellants , Ibid, paper 2.6, pp 281-99 (1975) 243) R.A. Benham F.H. Mathews,... 

Thermal Decomposition of Ammonium Perchlorate During Gamma-Ray Irradiation , Defense Nuclear Agency Rept DNA 4032P-3,... 

Insights on the Thermal Decomposition of Ammonium Perchlorate from Studies on Very Large Single Crystals , Proc 8th Intern Symp on Reactivity of Solids, Gottenberg, Sweden (1976)... 

Al Fakir, M. S., Progr. Astronaut. Aeronaut., 1981, 76, 5512—564 Admixture of lithium perchlorate [1] or zinc perchlorate [2] leads to decomposition with explosion at 290° or ignition at 240°C, respectively. The role of ammine derivatives of lithium and magnesium perchlorates in catalysing the thermal decomposition of ammonium perchlorate has been studied [3], and lithium perchlorate has a strong catalytic effect on the burning rate [4]. 

L.L. Bircumshaw, B.K Newman "The Thermal Decomposition of Ammonium Perchlorate I. Introduction, Experimental, Analysis of Gaseous Products and Thermal Decomposition Experiments," Proc. Roy. Soc. (London) A227 (1954) 115-132 ibid, "The Thermal Decomposition of Ammonium Perchlorate II. The Kinetics of the Decomposition, the Effect of Particle Size, and Discussion of Results" A227 (1955) 228-241. L.L.Bircumshaw, T.R. Phillips, "The Kinetics of the Thermal Decomposition of Ammonium Perchlorate" J. Chem. Soc. 122 (1957) 4741-4747. 

W.A. Rosser, S.H. Inami, H. Wise, Thermal Decomposition of Ammonium Perchlorate, Combust. Flame, 12 (1968) 427-435. 

M. D. Pace, Nitrogen Radical from Thermal and Photochemical Decomposition of Ammonium Perchlorate, Ammonium Dinitramide, and Cyclic Nitramines, M. R. S. Proceed, 296 (1993) 53-60. 

A. V. Rayevskii, in Mechanisms of Thermal Decomposition of Ammonium Perchlorate, Inst. Chem. Phys. Acad. Sci. USSR, Chernogolovka Branch, 1981, p. 30. 

Nitronium perchlorate, as an ion complex may exist as a transitory intermediate, which may either revert to ions, sublime, or decompose. A similar mechanism has been proposed for the decomposition of ammonium perchlorate (3). 

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