Explosion Decomposition Calorimetry

Nitrogen trifluoride is a kinetically inert gas, but when sparked or heated can fluorinate substrates and release nitrogen. Sulfur, for example, is quantitatively converted to SFg using NF3 at 5 atm (231). Similarly, boron is converted to BF3 (159) and CF3CN to CF4 (232). Nitrogen trifluoride has some advantages over difluorine. It is safer to handle, and double-compartment bombs to avoid self-ignition are not required. However, some self-dissociation has to be measured and corrections made. 

Explosive hydrogenation has been employed with gaseous fluorides and the liberated HF dissolved in situ in water. This requires a platinum-lined bomb to minimize corrosion. 

Phosphorus trifluoride has been used as a reactant gas in calorimetry to act as a fluorine acceptor rather than donor. The heats of formation of xenon fluorides have been calculated from the reaction heats (237)  

The xenon fluorides, especially the difluoride, could also be used as calorimetric gases with possible applications for organic fluorides or metal carbonyls [e.g., Mo(CO)g - Mo(CO) Fg.. MoFg]. 

The heats of formation of the fluoroamines CF (NF2)4 (213), CF2(0F)2 (91), KrF2 (109), and F2O2 (146) have been determined by thermal decomposition. 

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Reactivity (instability) information Acceleration rate calorimetry Differential thermal analysis (DTA) Impact test Thermal stability Lead block test Explosion propagation with detonation Drop weight test Thermal decomposition test Influence test Self-acceleration temperature Card gap test (under confinement) JANAE Critical diameter Pyrophoricity... 

A more detailed investigation of the thermal behavior of the exploding [ ]rotanes by differential scanning calorimetry (DSC) measurements performed in aluminum crucibles with a perforated lid under an argon atmosphere revealed that slow decomposition of exp-[5]rotane 165 has already started at 90 °C and an explosive quantitative decomposition sets on at 150 °C with a release of energy to the extent of AH(jecomp = 208 kcal/mol. Exp-[6]rotane 166 decomposes from 100°C upwards with a maximum rate at 154°C and an energy release of AH(jg on,p=478 kcal/mol. The difference between the onset (115°C) and the maximum-rate decomposition temperature (125-136°C) in the case of exp-[8]rotane 168 is less pronounced, and AHjecomp 358 kcal/mol. The methy-... 

The perfluoroammonium cation can be stabilized with a large number of different anions in the form of stable salts these anions are derived mainly from perfluorinated Lewis acids. The NF4 salts are prepared directly from NF3 or by conversion of readily accessible NF4 salts. They are crystalline, moisture-sensitive materials, and usually soluble in HF. Various techniques have been applied to characterize them Infrared, Raman, F NMR, and ESR spectroscopy, X-ray diffraction, calorimetry, and elemental analysis. Decomposition to NF3, F2, and a Lewis acid takes place at elevated temperatures. Therefore, NFJ salts are principal ingredients in solid NF3-F2 gas generators, for example, for HF chemical lasers and in high detonation pressure explosives. 

Kishore, K. (1977) "Thermal decomposition studies on Hexahydro-1,3,5-trinitro-s-triazine (RDX) by differential scanning calorimetry", Propellants and Explosives 2, 78-81. 

Whelan, D.J., Spear, R.J., Read, R.W. The thermal decomposition of some primary explosives as studied by differential scanning calorimetry. Thtamochim. Acta 80, 149-163 (1984)... 

The Arrhenius constants to describe the thermal decomposition are a subject of much debate. Rogers has used his differential thermal calorimetry technique to obtain the constants, and the experimental and calculated critical temperatures for several explosives are compared in Table 3.1. 

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