Ignition temperature cyclonite

According to Avogadro [19] the ignition temperature of cyclonite is 215°C (this author reports 185°C for penthrite). T. Urbanski and Pillich [20] found the following values for ignition temperatures ... 

As an explosive octogen is superior to cyclonite in that its ignition temperature is higher (an explosion ensues in 5 sec at 335°C while with cyclonite this occurs at 260°C). The chemical stability of octogen is also superior. In a vacuum, at 120°C in 40 hr octogen evolves 0.4 cm3 of gas (cyclonite 0.9 cm3) at 150°C it evolves 0.6 cm3 of gas (cyclonite 2.5 cm3). Thus, at 150°C octogen possesses a stability of the same order as trinitrotoluene or picric acid. 

In the United States a mixture of 60% cyclonite and 40% TNT was used under the name of Cyclitol as a filling for aerial bombs. The density of the cast explosive was 1.65-1.70, its rate of detonation 7800 m/sec, and in the ballistic pendulum it gave a value of 130 (100 for TNT). In the United States this mixture is considered to be only a little more sensitive to impact than TNT with a stability similar to that of cyclonite. This does not agree with T. Urbanski s [5] investigations according to which the sensitiveness to impact of such a mixture, in a powdered form, and its ignition temperature (225°C) approximate to the corresponding values for tetryl. 

Table 45 and the graphs in Figs. 65 and 66 summarize T. Urbanski s findings on the rate of detonation, the lead block expansion, the sensitiveness to impact and the ignition temperatures of powdered mixtures of cyclonite with TNT, of various composition. 

Fig. 66. The relation between the ignition temperature and sensitiveness to impact of mixtures of cyclonite and TNT, and their composition (according to T. Urbanski [6]).

Fig. 76. The influence of sulphur on ignition temperature of nitro compounds and cyclonite (according to T. Urbanski and Pillich [92]).

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