Nitric esters stability

It was shown by the above authors that nitrogen content of nitric esters such as NG or NC cannot be determined by the nitrometer method, if stabilizers such as centralite are present, because centralite absorbs some nitrogen oxides thus giving a low result for N. The difference between the nitrometer N content of NG in absence of a stabilizer and N content of NG in presence of a stabilizer may be taken as an index of stabilizing action of the stabilizer the bigger the difference, the better the stabilizer. This difference is called indice nitrometrique... 

Explosive Compositions, Brisont (of High Density). The following expl compns con eg solid TNT and liquid nitric esters are described. Nitroglycerin 15—20, soluble Nitrocellulose 0—7.5, Kieselguhr 0—5, stabilizer 0-2.5, TNT 85-70%. The TNT is in the form of crushed flakes Ref J. Taylor and S.H. Davidson, BritP 578371 (1946) CA 41, 1842 (1947)... 

Explosiveness and Constitution, According to Majrich, the explosiveness depends not only on the nature of the carbon chain, but alsd on other groups. For instance the aldehyde, Keto and carboxylic groups lower the brisance, sensitiveness and stability, especially in nitric esters and the stability seems to increase with increasing mol wt Ref A. Majrich, Chem Obzor 7, 104-8,... 

CDj) T. Urbanski, Vol 2(1965), pp 22-31 gives methods for determining the Stability of Nitric Esters, which include Abel Heat Test, Litmus Test (Vieille Test), Heat Test at 134.5°C, Silvered Vessel Test, Loss of Weight Test, Will Test, Bergmann Junk Test and Manometric Test... 

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. 

At a temperature below the melting point nitroguanidine is said to be relatively stable—more so than nitric esters and similar in stability to aromatic nitro compounds. 

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. 

The majority of the stability tests for smokeless powder are much the same as the methods used to determine the stability of nitric esters, in particular nitrocellulose (Vol. II). They are based on heating samples of the powder, thus starting decomposition processes or hastening processes already initiated within the powder. The value of such methods is comparative, since at an elevated temperature different reactions occur than those which would arise under normal conditions of storage. Nevertheless experiments over many years have shown that certain interrelations may be established for the stability of powder at various temperatures. Vieille [61] reports that the heating of a sample of powder for 1 hr at a temperature of 110°C involves approximately the same decomposition as ... 

In addition to the testing methods common to nitric esters (nitrocellulose, nitroglycerine) and smokeless powder there are also methods used exclusively for testing the stability of smokeless powders. 

Stabilization of nitric esters of polyhydric ales (such as mixts of NG with NGc) for use in Dynamites, was achieved by incorporating small amts of acetylacetone, benzoylacetone, or phloroglucinol. Mixt of NG 60 NGc 40% stabilized with 1% acetylacetone withstood Abel stability test for >300 mins]... 

Alkalies, Action on Stability of Nifroco ( loses. See under Alkalies, Action on Nitric Esters... 

Residual alkalinity in expls and in propellants is undesirable because even traces of alkalies may lower the stability and mp of an expl with a resulting increase in exudation. Alkalies also may form products which are more sensitive than the original expl.Some discussion on this subject is given under Alkalies, Action on Nitric Esters and... 

All methods of determining the stability of explosives and particularly of nitric esters consist in examining the behaviour of the substances at an elevated temperature. It is obvious that the most reliable methods of determining stability are those which are carried out at lower temperatures approaching the ordinary room temperature. 

Bacteria and Mold Action on Nitric Esters and on Smokeless Propellants Influence of microorganisms upon stability of NC was studied as... 

Symmes, in a footnote, p. 375, in his English translation of Naoum s book, op. cit., cites U. S. patents 1,307,032, 1,307,033, 1,307,034, and 1,371,215 which describe a method for the manufacture of mixed ethylene and propylene glycols from cracking gas, satisfactory methods for the nitration of the mixture and for the stabilization of the mixed nitric esters, and explosives made from the products which practical tests in actual use showed could not be frozen even at temperatures prevailing in winter along the Canadian border, or —10° to —30° F. ... 

There are many other variations of the heat test.101 They are sometimes called stability tests, but most of them, it will be noted, involve the self-catalyzed decomposition of the sample in an atmosphere of air or of red fumes. They indicate the comparative stability only 6f materials which are physically alike. True indications of the stability of nitric esters are to be secured only by studying the decomposition of the substances in vacuum. For this purpose the 120° vacuum stability test is most generally preferred. 

A number of such compds were prepd and then converted to the corresponding nitric esters by Wolfram et al of Ohio State Univ while working under a US Ordnance Corps contract(Ref 5 6). They found that all the pentanitrates prepd by them could be detonated by gentle heat or by a hammer blow on steel. Thermal stability tests have shown that the aldonamide pentanitrates are more stable than aldonic acid pentanitrates or their methyl esters and that the esters were less stable than the corresponding acids. All of their purified nitrates underwent rapid decompn at their mp s, accompanied by violent bubbling and evolution of nitrogen oxides. No residue was visible after decompn... 

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