Nitric esters as explosives

Ropuszynski [76] suggests two distinct aspects of stability, namely chemical stability—which ought to be understood as the stability of the pure chemical compound and practical stability—that characterizes a product stabilized by methods applied in practice. 

In accordance with these definitions a substance possessing good chemical stability may still be of insufficient practical stability if it is not fairly pure. 

Hydrolytic decomposition has already been discussed. A different type of decomposition of nitric esters occurs at elevated temperatures. More detailed information concerning this type of decomposition will be included in the descriptions of the individual esters properties, in particular those of nitroglycerine and nitrocellulose. 

The decomposition of esters at elevated temperatures is of exceptional practical importance, since it has often been responsible for accidents. Investigations of the decomposition of esters at elevated temperatures by laboratory tests serve as a rapid method of estimating their stability. 

A number of authors have tried to express the decomposition rate of nitric esters in mathematical formulae. Thus Berthelot [77] expressed the relation between the decomposition rate of nitric esters and the temperature as  

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Physical properties Dipole moments Spectroscopy Hydrolysis of nitric esters Reduction of nitric esters Some 4>thcr reactions of nunc esters Form Jlion of nitric esters Nitric esters as explosives C hemical stability... 

C. P. Spaeth, 29, 5660 (1935) Ignition composition for the top charge in blasting caps, comprised of NC impregnated with a liquid explosive nitric ester, such as NG and KC103 USP 2007223 (1935)... 

Explosive Nitric Esters, Liquid. Spout wash water formed in the mfg of liquid expl nitric esters is created with a non expl aromatic nitro hydrocarbon e. g. 0-Nitro toluene (1), to extract the expl esters and render the wash water safe for disposal. Wash water from a Nitro glycerine (II) plant contg 0-35% II was treated at a rate of 25000 lbs/8 hrs with 1000 pounds of (I) which was continuous ly recycled so as to give a 2 1 wash water I vol ratio Ref W.G.Allan et al, Brit P7345 2 3 (1955)... 

As regards explosive strength, nitramines occupy a position midway between nitro compounds and nitric esters. They also hold a central position regarding other properties, such as chemical stability and sensitiveness to impact and friction. 

It was also suggested recently that fusible explosives should be used instead of semi-fusible ones. For this purpose TNT is replaced as a component by relatively low-melting nitric esters. 

Strong bases have an adverse effect on the stability of smokeless powder as described above. Moreover, Angeli [59] found that pyridine and its homologues cause decomposition of nitrocellulose. (On the action of pyridine on other nitric esters see Yol. II.) At an elevated temperature (e.g. 110°C) pyridine can produce an intense denitration of esters which may even lead to an explosion. 

In completely colloidal nitroglycerine and nitrodiglycol powders these nitric esters are non-volatile, explosively active solvents. Similarly, triethylene glycol dinitrate (nitrotriethylene glycol) is used as an ingredient in some powders without a volatile solvent. 

PETN (2.13), also known as pentaerythritol tetranitrate (C5H8N4012), is the most stable and the least reactive of the explosive nitric esters. It is insoluble in water, sparingly soluble in alcohol, ether and benzene, and soluble in acetone and methyl acetate. It shows no trace of decomposition when stored for a long time at 100 CC. It is relatively insensitive to friction but is very sensitive to initiation by a primary explosive. 

Esters of monovalent alcohols and nitric acid do not play a large part as explosives. Among the polyvalent alcohol esters most useful for that purpose glycerol nitrates and glycol nitrates are especially important. 

The most important of the carbohydrate esters of nitric acid are the polysaccharide nitrates, particularly cellulose nitrate or nitrocellulose (NC) and starch nitrate ( nitrostarch ) which is much less used. Nitric esters prepared from other sugars such as saccharose and lactose are not of any importance as explosives. 

Long ago, such widely occurring and readily available carbohydrates as glucose, lactose, galactose, and saccharose attracted the attention of chemists, who examined these substances to find out whether they were suitable raw materials for manufacturing explosives, in the form of nitric esters. 

Naoiim [68] has drawn attention to the nitric acid salts of ethanolamine nitric esters (O-nitrated etlianolamines), i.e. mono-, di- and triethanolamine nitrate salts, as substances suitable for explosives. Nitration of a mixture of all three ethanolamines furnishes an oil-like, insufficiently stable product, readily decomposed with the evolution of oxides of nitrogen. The individual substances are crystal products soluble in water, in which they are hydrolysed. e... 

Almost without exception the nitro compounds and nitric acid esters used as explosives are toxic. The degree of toxicity varies widely with the material in question, but most are capable of causing acute distress if taken orally. Nitroglycerin has a small medical use as a vasodilator. 

At present nitration is one of the most widely applied direct substitution reactions. This is due to several factors. For example nitration usually proceeds easily, its products can readily be separated from the spent acid, said there is a wide range of possibilities in the practical use of nitro compounds, both as intermediates and end products. The presence of a nitro group in the starting product made it possible to obtain a number of basic organic intermediates such as aniline said benzidine. Dyes with more than one nitro group, such as picric acid were obtained. It has been found that higher nitrated nitro compounds and nitric acid esters have explosive properties and are of practical importance. Some nitro compounds are used in perfumes. Medicinal properties have lately been discovered in certain nitro compounds, eg. chloramphenicol. 

Nitroalcohols X and XI may be utilized as starting materials for the manufacture of nitric acid esters having explosive properties (see Vol. II). In the presence of primary or secondary amines or ammonia the reaction leads to formation of aminonitroalcohols (XII)... 

It is also hoped that in widening the scope of the book, it might become useful not only to students Mid experts on explosives, but also to all who Me interested in the chemistiy of such substances as nitro compounds, nitrMnines, nitric esters, nitric salts, azides etc. that may serve as intermediates for organic reactions. 

The simultaneous presence of nitric acid and alcohol in the ether extract must be avoided as explosive oxidation might occur during evaporation of the ether. Furthermore, the presence of alcohol may lead to contamination of the product with traces of the acid ester. 

Properties Nitroglycerine high explosive known today. Howrever, there are many other similar liquid nitric esters which have the same explosive properties as NG. Many of these have somewhat inferior blasting power to that of NG (a few are superior) but are more stable towards mechanical shock than NG itself. PGDN is just one such compound, being at least ten times more stable towards mechanical shock than NG. Under the falling weight test, NG detonates at... 

Most explosives consist either of a mixture of carbon compounds limits from o i to 0 3 per cent, are given potassium nitrate containing with compounds rich in oxygen, or of organic compounds such as nitrites under 0 5 per cent, did not increase the sensitiveness of gun-nitro compound and nitric esters, which contain the oxj en necessary powder and synthetic nitrates were found to be as suitable as material for their combustion. A smaller class of explosives includes substances prepared from Chili nitrates. 

Nitric esters undergo gradual decomposition on storage. Stalulity tests are therefore necessary as a control of the safety of e q>l< ivcs of this type. The tests are applied during manufacture and to the finished explosive and they may also be applied at intervals during storage, especially in hot climates. 

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