Stability of Explosives

Detonation (and Explosion), Stability of Explosives. Andreev 8t Belyaev (Ref 1, p 106) stated that stability, of explosive (stoykost vzryvchatogo veshchestva) is determined by the rate of changes in its physical and chemical (and consequently of explosive) properties with duration of time. The smaller the rate, the more stable is explosive and vice versa 

There are two types of stabilities chemical and physical 1) Chemical Sttzhility is characterized by the rate of decomposition of expl as a result of chemical changes. The most common is thermal stability which can be detd either at low temps (such as temps encountered in storage) or at higher temp. Results of heat tests can be tabulated and graphically represented by two methods. In the 1st method (See Fig, curves a) the time required for formation of a known quantity, Xj, of products of decomposition is determined, while in the 2nd method (See Fig 1, curves S) the amount of products of decomposition X2 during fixed time t2 is detd. Curves I II deal with two different expls 

Fig 2 Apparatus of Lambrey for. testing Chemical Stability of Explosives 

The apparatus used by Lambrey is shown on Fig 2. It consists of a glass tube, 1, in which is placed 8.5 g expl sample E. 

To the flat neck of the tube is attached (by means of picein) to the neck of tube, 2, (60 mm long), which is provided with the stopcock, 4, and two quartz windows, 3, for optical observation of nitrogen oxides density. After loading the tube, 1, with expl and assembling it together with tube, 

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Symposium on Chemical Problems Connected with the Stability of Explosives, Kungalo, Sweden, June, 1982. 

J. Isaksson and L. Rittfeldt, "Chaiacteiization of Black Powdeis," Proceedings of 3rd Symposium on Chemical Problems Connected with the Stability of Explosives,]oDkofmg, Sweden, 1952, p. 242. 

H.H. Licht, Symp on Chem Problems connected with Stability of Explosives, Tyringe, Sweden (1970), p 177 45) C-H. Johansonn... 

Yoshida, T., M. Itoh, K. Tohyama, and M. Tamura, "The Correlation of DSC Data with Other Test Data," Chemical Problems Connected with the Stability of Explosives, 5, Part 1,79 (1979). 

W.H. Rinkenbach A.J. Clear, Standard Laboratory Procedures for Sensitivity, Brisance and Stability of Explosives",... 

A.J. Clear, "Standard Laboratory Procedures for Determining Sensitivity, Brisance and Stability of Explosives", PATR 3278 (Dec 1965) [Superseding PATR FRL-TR-25 (l )6l] Impact Test with Picatinny Arsenal Apparatus (pp 2-4 and Figs 1, 2, 3 4, pp 32-35) Impact Test with US Bureau of Mines Apparatus (pp 4-7 and Figs 5, 6 7, pp... 

K.K. Andreev V.V. Gorbunov, Vsesoyu-znoyeKhimicheskoyeObshchestvo.Zhurnal 8(5), 592(1963) (Effect of pressure on combustion stability of explosives)... 

I) J. von Meerscheidt-Hiillesem, SS 34, 167-70(1939) CA. 33, 7569(1939) (Determination of the chemical stability of explosives including smokeless propellants with the aid of Winkler gas buret)... 

GH) A.J. Cleat, "Standard Laboratory Procedures for Determining Sensitivity, Brisance and Stability of Explosives , PATR 3278 (1965), FREL, Picatinny Arsenal, Dover,... 

Temperature of storage It has been established by a number of investigators notably Will [24], Robertson [25], Farmer [26-28] and Hinshelwood [29] that all explosives undergo a thermal decomposition at temperatures far below those at which spontaneous explosion occurs. Therefore, decomposition reactions are of considerable importance in determining stability of explosives and it can be determined by measuring their rate of decomposition at elevated temperatures. 

Introduction of Amino Groups The introduction of an amino (-NH2) group (in ortho position) into a benzene ring already having a nitro (-N02) group is one of the simplest and oldest approaches to enhance thermal stability of explosives [35-37]. This is evident from the study of the effect of introduction of amino groups in trinitrobenzene (TNB) [Structure (2.18)] to form monoamino-2,4,6-... 

A detailed account of the compatibility and stability of explosives-definition, implications and effect of various parameters such as temperature of storage, chemical constitution of explosive vis-a-vis other ingredients, sunlight and electrostatic discharge etc has already been given in Chapter 1 (Section 1.4.1). In this section, the test methods used to determine compatibility and stability are discussed. 

The vacuum stability test and heat test are the most common tests used to determine the compatibility and stability of explosives with polymers or contact materials. However, an impact sensitivity test is sometimes used in order to derive additional information. 

International Test at 75°C. This test, recommended by the International Commission which repotted to the 8th International Congress of Applied Chemistry, 1912, on "Methods for Testing the Stability of Explosives" is conducted as a supplement to the Abel Test. The test is described in Vol 1 of Encycl (Ref 9, p XVIII) and in Ref 1, pl2... 

Miles, JCS 1931 2532-42 (Formation and characterization of crysts of LA and some other initiating expls) 5)K.S.Warren, PATR 1152 (1942), "Study of the Action of Lead Azide on Copper 6)J.Fleischer J.B. Burtle, USP 2,421,778 (1947) "Initiating Explosives 7)Wm.H.Rinkenbach A.J. Clear, PATR Rev 1(1950), "Standard Laboratory Procedures for Sensitivity, Brisance and Stability of Explosives 8)U.S.Military Specification MIL-L-3055, Amend 1(1952) (Requirements and tests for dextrinated lead azide) 9)J-Bernstein, GLR 51-HI-2332, Pic Arsn (1952) "Hygroscopicity of Dextrinated Lead Azide 10)J.W.Lavitt, PATR 1957 (1953), "An Improved Microscopic Method for the Determination of the Crystal Size Distribution of 2-Micron RDX" 11)F.P. Bowden K.Singh, Nature 172, 378(1953) (Size effects in the initiation and growth of explosives) 12)J.W.C.Taylor, A.T.Thomas... 

CA 40, 2764(1946)(Polaro-graphic detn of azide ion in general and in LA in particular) 5)D.F.Vasil ev, Trudy-KomissiiAnalKhim, OtdelKhimNauk, 2, [5], 90-5(1949) St CA 44, 9300-1(1950) (Polarogra-phic detn of Pb content of LA) 6)IJS Military Specification MIL-L-3Q55(1949) an Amendment 1 (1952) (Requirements for crystalline LA intended for use in manuf of detonators, fuzes and priming compns) 7)W.H. Rinkenbach A. J.Clear, "Standard Laboratory Procedures for Sensitivity, Brisance and Stability of Explosives", PicArsnTech Rept 1401 (1944), Revised in 1950 8)J. 

Vacuum Stability Test was designed by Faraer(Ref 1) for detn of stability of explosives and propellants. In this tear the thermal decompn of a sample is followed by observing the rise In pressure of the gases given... 

P or Pat PA or PicArsn PACLR PAGLR PACT PAMR or picArsnMemRept Partington(1950) Pascal(1930) PATR or PicArsnTech Rept PATR 1401(Rev 1)1 (1950) i Patent Picatinny Arsenal, Dover, NJ Picatinny Arsenal Chemical Laboratory Report Picatinny Arsenal General Laboratory Report Prevention des Accidents-Con troles Techniques(Bruxelles) Picatinny Arsenal Memorandum Report J.R.Partington, "A Textbook of Inorganic Chemistry, Macmillan, London(l95( P.Pascal,"Explosifs, Poudres, Gaz de Com bat, Hermann, Paris(1930) Picatinny Arsenal Technical Report, Dover, New Jersey Wm. H.Rinkenbach A.J.Clear, Picatinny Arsenal Technical Report No 1401, (1950), "Standard Laboratory Procedure for Sensitivity, Brisance and Stability of Explosives ... 

Vacuum Stability Test. See in Vol 1, Introduction , TV XXVI, and under Stability and Instability of Explosives in Vol 6, E438-R Addnl Refs 1) AJ. Clear, Standard Laboratory Procedures for Determining Sensitivity, Brisance and Stability of Explosives , PATR 3278 (Rev 1) (1970), 18-28 2) R. Meyer,... 

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. 

A full description of the methods of determining the stability of explosives are given in books dealing with analysis of explosives, such as Kast and Metz [82], Clift and Fedoroff [83], Olsen and Greene [84], and Avanesov [85]. 

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