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Abstract
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or the first time, the thermal decomposition behavior of heterogeneous mixtures of ammonium perchlorate (AP) with two organic additives – 4, 4’-Bipyridine, and biphenyl – were investigated. The heterogeneous mixtures of the additives and ammonium perchlorate were prepared by dissolving 1, 2, 3, 4, and 5 mg of the organic additives and 100 mg ammonium perchlorate in 2 ml of methanol as solvent. After that, the thermal decomposition behavior of prepared solid heterogeneous mixtures was monitored by thermogravimetry analysis, differential scanning calorimetry, and mass spectrometry analysis. The effect of the 4, 4’-Bipyridine on thermal decomposition of AP enhanced the released heat from 479 to 1842 J g−1 and produced a decrease of decomposition temperature from 433 °C to 308 °C while the thermal decomposition of AP in the presence of biphenyl did not change as dramatically as it did with 4, 4’-Bipyridine. With biphenyl, the decomposition temperature was found to be similar to that of pure AP and the evolved heat was about 718 J g−1. The gaseous products of decomposition of 4, 4’-Bipyridine /ammonium perchlorate were monitored by mass spectrometric analysis. The main evolved decomposition gases of pure AP are N2O, O2, Cl2, ClO, ClO2, ClO3, HClO4, and HCl, while the major gaseous products of the 5:100 (w/w) mixture of 4, 4’-Bipyridine with AP were detected as N2, NO, N2O, O2, Cl2, ClO, ClO2, ClO3, HClO4, HCl and 4, 4’-Bipyridine. The change in the composition of volatile products indicates a change in the mechanism of AP decomposition from proton transfer to electron transfer in the presence of 4, 4’-Bipyridine.
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