Lead styphnate, decomposition

Styphnic acid is a nitrogen compound. Lead styphnate monohydrate was found to detonate at 229°C (444°F), but the course of decomposition could be followed at 228°C and below. 

Thermal decomposition of pure explosives such as primary explosives lead azide, lead styphnate, mercury fulminate etc. [35], monomethylamine nitrate [36] and explosive mixtures RDX + HMX mixtures [37]. 

A number of authors have investigated the thermal decomposition of lead styphnate Hailes [48] examined the decomposition of this substance within the temperature range 200 to 228°C, and Gamer, Gomm and Hailes [49] derived the following equation for the decomposition curve ... 

Tompkins and Young [50] examined the thermal decomposition of barium styphnate and found it to be similar to that of lead styphnate hydrate (Fig. 54). 

According to T. Urbanski and Kruszynska [41] thallium styphnate has similar properties to those of lead styphnate. The former, however, is much more sensitive to impact than the latter. Their sensitiveness to temperature is similar contact with a metal surface heated to 351°C causes explosion after 1 sec. The activation -energy of thermal decomposition is nearly 80 kcal/mole. 

Effects of Reactor Irradiation Upon the Subsequent Thermal Decomposition of Lead Styphnate , JPhysChem 66,416 (1962)... 

Flanagan [140,141] has also studied the dehydration and decomposition of lead styphnate. The products of decomposition were identified as COj Nj NO in the ratio 3.1 1 0.4 and discrete nuclei could not be identified in microscopic examination of partially decomposed salt. The shapes of ar-time curves for reaction in 0.8 Torr water vapour were significantly different from those in vacuum. This was attributed to differences in the physical structure of the reactant. In water vapour the rate of reaction was approximately constant up to ar = 0.8, ascribed to an initial rapid... 

However, when lead azide, lead styphnate, mercury fulminate, RDX, TNT, and PETN were subjected to bombardment with a negative pion beam, no explosions or decompositions were observed for any of the explosives. The analysis had predicted initiation only for RDX. Also it had indicated that nuclear fission events would produce higher energy densities and greater temperature increases than were actually observed. 

A total neutron exposure of 2.2 X lO n/cm enhanced the decomposition of lead styphnate monohydrate by a factor of three [55] (Figure 10), the rate increasing monotonically with the amount of exposure. A sample decomposed 8 days after irradiation produced a decomposition curve almost identical with one stored 46 days after irradiation. 

Figui-e 10. The thermal decomposition curves of reactor-irradiated lead styphnate monohydrate (222.5°C) [55]. 

In the spectrum of lead styphnate [37], lead oxide appeared as an emitting species at about 5 cm from the sample, resulting in a reaction of atomic lead with oxygen present in the air. Flushing the explosion chamber with helium restrained the formation of lead oxide. No large fragments, sometimes observed in thermal decomposition analysis, were found. 

Flanagan, T.B. Effect of nuclear irradiation upon the decomposition of lead styphnate monohydrate. Nature 181, 42-43 (1958)... 

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