Nitroglycerine decomposition

This has been confirmed in a recent reports by Andreyev, Glaskova, Maurina and Svetlov [60], According to these authors the activation energy of nitroglycerine decomposition at 140-150°C is E = 45.0 kcal/mole (log10 B = 20). 

Exothermic oxidation—reduction reactions provide the energy released in both propellant burning and explosive detonation. The reactions are either internal oxidation—reductions, as in the decomposition of nitroglycerin and pentaerythritol tetranitrate, or reactions between discrete oxidizers and fuels in heterogeneous mixtures. 

Pure nitroglycerin is a stable Hquid at temperate conditions. It decomposes above 60°C to form nitric oxides which in turn catalyze further decomposition. Moisture increases the rate of decomposition under these conditions. Double- and multibase propellants containing nitroglycerin have substantially shorter stabiHty Hves at 65 and 80°C than do single-base propellants. The decomposition of nitroglycerin proceeds as... 

O. E. Wating and G. Krastins, The Kinetics and Mechanism of Thermal Decomposition of Nitroglycerin, Report 5746, NOL, White Oaks, Md., 1958. 

Nitroglycerin (NG) production provides a good example of the reductions in inventory that can be achieved by redesign. It is made from glycerin and a mixture of concentrated nitric and sulfuric acids. The reaction is very exothermic if the heat is not removed by cooling and stirring, an uncontrollable reaction is followed by explosive decomposition of the NG. 

The approach taken in the development of an analytical model for the combustion of double-base propellants has been based on the decomposition behavior of the two principal propellant ingredients, nitrocellulose and nitroglycerin. The results of several studies reviewed by Huggett (HI2) and Adams (Al) show that nitrocellulose undergoes exothermic decomposition between 90° and 175°C. In this temperature range, the rate of decomposition follows the simple first-order expression... 

Like nitrocellulose, nitroglycerin also undergoes a slow first-order exothermic decomposition at temperatures below 140°C. As the pressure is increased, this decomposition reaction is followed by a sudden explosive reaction. Evidence suggests that the explosive reaction is autocatalyzed by the accumulation of N02. The combined results of several studies indicate that... 

C04-0138. Compounds that undergo explosions typically produce large quantities of hot gases from much smaller volumes of highly reactive solids or liquids. Balance the reaction for the decomposition of nitroglycerine, a violent explosive C3 H5 N3 Og(/) N2(g) + C02(g) + H2 0(g) + 02(g)... 

Dilution or simple mixing with a stable compound is sufficient to stabilise an unstable substance. In the case of a simple mixture with a neutral substance, this stabilisation process is called desensitisation . Thus hardeners such as benzoyl peroxide are nomially in the form of suspensions in heavy esters or oils. This peroxide is mixed with 30% of water by weight. Dynamite is nitroglycerine stabilised with the help of a neutral material. In all these cases, heat that is produced by the potential beginning of decomposition is absorbed by the inert substance. 

When mixed with potassium chlorate calcium dihydrogenphosphate detonates as violently as with decomposition of nitroglycerine. It is probably the result of the explosive decomposition of chlorine dioxide, which is formed because of the presence of acid radicals in the phosphate. 

Thus, nitroglycerin s explosive properties are caused by three factors the energy that is given off by its decomposition, the rate at which the reaction occurs, and the small amount of energy that is needed to initiate the reaction. In this unit, you will learn about the energy and rates of various chemical reactions. 

The chemical formula of nitroglycerin is C3O9N3H5. Write the balanced chemical equation for the decomposition of nitroglycerin, as described in this feature. 

FIG. 2.5 Ballistite, a "smokeless powder" consisting of 60% nitrocellulose and 40% nitroglycerine, produces a thermogram with no transitions detectable prior to exothermic decomposition above 150 "C. 

Nitroglycerine 10a is both a drug and an explosive. Its inclusion into the cavity of p-cyclodextrin, p-CD, 11 prevents its decomposition and enhances its bioavailability [14]. The complex of 10a with 11 is marketed under the name Nitropen as a coronary dilator sublingual tablets by Nippon Kayaku company in Japan. 

The calculated thermal effect in this reaction (ca. 1250kcal/kg) would fall between those of the explosive decomposition of nitroglycerine and guncotton, and the calculated temperature would be ca. 2500°C. 

The products of decomposition of smokeless powder resemble those formed by the decomposition of its ingredients, i.e. nitrocellulose or nitrocellulose with either nitroglycerine or dinitrodiglycol. 

J. Taylor [27] drew up the following table of the heat of explosive decomposition, the gas volume and rate of burning of British nitroglycerine (double base) and American nitrocellulose (single base) powders (Table 166). 

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