Abstract
The degradation of the nitrate oxidant was followed in the course of the aging process of tracer pyrotechnic mix containing 22.0 % Mg, 46.0 % Sr(NO~3~)~2~, 22.0 % KCIO~4~, 9.0 % AlβMg alloy and 4.0 % organic binder. The accelerated aging was conducted under the conditions of the increased humidity (98.5 %, 85.0 %, 78.5 %) at the increased temperature (75 Β°C). Nitrate content as a function of aging time was calculated by substracting nitrite nitrogen from total nitrogen content determined by Devarda's alloy reduction method. The degradation products of the nitrate (nitrite and carbonate) were determined by UV/VlS (Griess reaction) and IR spectroscopy, respectively. Nitrate proved to have a great instability in the presence of the metal, the extent of its conversion to nitrite and carbonate being rather great in comparision to the previously studied alkali metal nitrates in the presence of Mg as well. The loss of the nitrate and the formation of the nitrite and carbonate are governed by the same kinetic laws as fuel degradation to the hydroxide. The rate of the metal oxidation to the hydroxide was faster than the rate of the nitrate degradation process. The failure of the mix is connected to the rather small content of the nitrite (0.4 %) while the texture was significantly destroyed.