Nitroglycerine freezing point

There are two modifications of nitroglycerine, differing in freezing point and crystalline forms. With respect to crystal structure the form melting at the lower temperature represents a labile form (Fig. 6) which can be transformed spontaneously into the higher melting stable form of nitroglycerine (Fig. 7). 

Freezing points for both variations of nitroglycerine, as published in different papers, are collected in Table 6. 

The freezing points of blends of nitroglycerine and nitroglycol have been investigated by Avogadro di Cerrione [30] who established experimentally that both substances can be dissolved in any quantitative ratio to form the following eutectic mixtures ... 

The problem of lowering the freezing point of nitroglycerine has been solved in many ways. Most of these methods are now of historical interest only, since they involved the use of substances which either weakened the explosive power of the nitroglycerine significantly or increased the price of product appreciably. 

This is another explosive suggested by Vender [22] for lowering the freezing point of nitroglycerine. 

Nitrostarcli manufactured by the Trojan Powder Co. German patent for use of glycol dinitrate to lower freezing point of nitroglycerine. 

Composition Dynamite with addition products to lower the freezing point of the nitroglycerine. 

Use and exposure Ethylene glycol dinitrate, also called nitroglycol, is a colorless to yellow, oily liquid. It reacts with acids and is used in the manufacturing of explosives to lower the freezing point of nitroglycerin, in order to produce dynamite for use in colder weather. 

A study of the preparation and properties of dinitrodiglycol was reported by Rinkenbach in 1927 and a further study of the nitration of diethylene glycol by Rinkenbach and Aaronson in 1931. Dinitrodiglycol is a viscous, colorless, and odorless liquid, specific gravity (x°/15°) 1.4092 at 0 , 1.3969 at 10°, and 1,3846 at 20 , freezing point —11.5 . It is completely miscible at ordinary temperatures with nitroglycerin, nitroglycol, ether, acetone,... 

Ethylene glycol yields on nitration a dinitrate which is used in conjunction with nitroglycerine to lower the freezing point. It is a colourless liquid which is less viscous than glycerine. It resembles glycerine in its hygroscopicity. 

Marqueyrol and Goutal have given methods for the estimation of dinitroglycol in nitroglycerine. These depend on the action of sulphuric acid and the depression of the freezing point of benzene. 

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