Stability of expls

Ref 9 contains a method for detg the chemical stability of expls and propints at 120° by collecting evolved gases in a burette and then analyzing them by titration or by detg the acidity of a w soln... 

P.A." Explosives. A variety of expl blends, patented by the firm of Bombrini-Parodi-Delfmo of Rome, consisting of PETN desensitized with pentaerythritol acetate. These expls can be cast below 100°, are less sensitive to shock than PETN, but more sensitive than TNT. Although they are less powerful and brisant than PETN, they are more so than TNT. Their stability is less than that of TNT. Their advantage in comparison with RDX formulations lies in the uniformity of the blend... 

Storage Stability of Manganese Delay Compositions , Expls Pyrots (The Franklin Institute Research Laboratories) 5, Nos 2 3 (Feb Mar 1972) 52) W.E. Perkins T.A. Doris,... 

Cook (Ref 1), in describing thermal decomposition of some HE s conducted in the quartz spring apparatus (described in Ref 1, p 175 and shown there in Figs 8.1a 8.1b), stated that PETN, RDX, Tetryl and to a small extent TNT decomposed autocatalyti-cally. EDNA followed the first-order decomposition law only until about 5% of the explosive had decomposed and then the reaction stabilized. The term autostabilization was applied here on the supposition that one of the condensed decomposition products of EDNA which accumulated in the explosive apparently tended to stabilize the bulk of expl and thus slow down the decomposition. After about 10% of the expl had decompd, however, the "autocatalysis developed. 

K.K. Andreev V.V. Gorbunov, ZhFizKhim 37, 1958-65 (1963) CA 59, 15113-14(1963) (Combustion-expln transition of expls. II. Stability of normal combustion of powdered... 

Stresau, PhysRev 87, 234(1952) CA 48, 8543(1954) (Low detonation velocity of certain primary expls) 9) R. Schall, ZAngewPhys 6, 470-75 (1954) ("Die Sta-bilitatlangsamer Detonationen ) The Engrg Index(1955), 362. Engl transin by Sgt A. Himsl, entitled "Stability of Detonations , Tech Transin No 20, Scientific and Technical Information Branch, FREL, PicArsn, Dover, NJ (1958) 10) T.C. Poulter, "A... 

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... 

Sessions 1-8 (Shock waves) Sessions 9-H (Development of deton from deflagration) Sessions 12-13 (Stability and sensitivity of expls) Sessions 14-15 (Structure of the deton wave) Session 16 - was not published Sessions 17-19 (Detonation in solid expls) Sessions 20-24 (Thermochemistry and energetics of deton) Session 25 (Measurement of deton pressure and of temp developed on deton) ... 

In the first phase of investigation, properties (such as mp, 5-sec expln temp, gas evoln at high temps a nd va cuum stability) of about 150 expls were tabulated and out of this list the following were selected as more likely to withstand sterilization ... 

Chem Expls , June 1963 4) W.C. Davis, preprints Proc 4th Symp on Deton p A-41 (1965) 5) H.H. Licht, Sympos on Chemical Problems connected with the Stability of Explosives, Tyringe, Sweden,... 

Test tubes, each contg O.lg of a NC expl, are suspended in a bath of mineral jelly preheated to 100°. A strip of Kl-starch paper is suspended above the sample. Heating of the bath is continued, by raising the temp 5° per min, until the point is reached at which the test paper begins to color. This point is taken as an indication of the stability of the NC proplnt. 

Loss of Weight Stability Tests. Expls are heated at some predetd temp and the loss of weight is measured periodically. Usually, the greater the weight loss, the less stable is the expl... 

Diffusion Flame. When a slow stream of fuel g s flows from a tube into the atmosphere, air diffuses across the boundary of the stream and Brms an envelope of expl mixture around a core of gas. The core decreases in height until it disappears at some distance above the tube. It thus assumes the shape of a cone. On ignition, a flame front spreads thru the mixture and stabilizes itself around the cooe of fuel gas. The hydrocarbons in common fuel gases crack to form free C H. The shell of carbon-bearing gas so formed gives such flames their luminosity Turbulent Jet Flame. When a gas stream issues from an orifice above a certain critical velocity, it breaks up into a turbulent jet that entrains the surrounding air. The flame of such a jet consists of random patches of combustion and no cohesive combustion surface exists... 

Guanidine Chlorate (GuChl), H2N.C NH.NH2.HC105 mw 143-54, N 29- 23%, OB to CO2 and Cl2 -22.3% colorless crysts, mp 148°(dec, Ref gives 98—100° for apparently pure material) sol in w. May be prepd by the double decompn of Gu Sulfate and Ba Chlorate, and evapn of the resultant soln over a w bath until crysts appear. As indicated in Ref 4, the thermal stability is not very high. This material is a mild expl which burns away when touched with a flame or a drop of sulfuric acid (coned). The same Ref indicates that its impact sensitivity is comparable to PA. It was proposed (Ref 3) as a component of expl mixtures with such fuels as C, S, Si, Al and an oxidizer like K nitrate... 

Abel s Test or Kl—Starch Test was designed by Sir F. A.Abel to determine the stability of propellants and explosives. It involved heating a small sample of an expl in a test tube closed with a stopper provided with a hook on which is suspended a strip of KI—Starch paper, moistened at the upper half with 50% glycerin in water. The tube is heated in a constant temp bath and the time necessary to produce a slight brownish (or other) coloration at the border between the moistened and dry areas of the indicator paper is observed. The longer the time required the greater the stability of substance under test. The test is usually conducted either at 65.5° or 82.2°, but other temps may also be used. More detailed descriptions of the test are given under propellants and under some expls, such as TNT... 

Note The following information is included in Addnl Refs (See p 340) The Hercules Powder Co patented a method of coating AN with nitrates of metals such as Cu,Pb,Zn, Cd,Ni or Fe to increase its sensitivity to detonation (Addnl Ref A). Lindsey proposed sensitizing AN by coating it with such mate-erials as finely divided Al(Addnl Ref B). McGill examined, during WW II, the thermal stability of AN s melting betw 163 1690 and found that at 100° and 135° the materials did not become acid and did not expl in 300 mins (Addnl Ref C).. The NatlBurStds detd some thermodynamic props of AN (Addnl Ref D). Societe Technique de Recherches et d Exploitation (Addnl Ref E) proposed to treat... 

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... 

Hygroskopizitac- or Feuchtigkeit Probe, in Ger). The hygt nature or property of a material to absorb moisture from its environment must be known if an expl is to be considered for military or commercial use. Absorption of moisture can have an adverse effect on the sensitivity, stability, or reactivity of expls. This property should be negligible to very low absorption for most expls... 

In a search for a greater variety and more effective desensitizers, a study was undertaken to investigate commercially available synthetic waxes (Ref 26). The study was primarily to determine the effects of these inert materials on the stability and expl characteristics of the more sensitive expls. Of 17 materials examined, the following four were found promising in rendering PETN less sensitive 90/10 Aristowax/Alox 600 Aristowax 150-5 Beeswax substitute 776 Pentawax 177 (85/15 pentaerythritol/dipenta-erythritol hexastearate)... 

Stability of the expl is better than that of the HBX made with NC and lecithin the sensitivity is unchanged... 

With the successful incorporation of about 5% wax in the HBX expl, trials were conducted in attempting to similarly desensitize other cast expl materials (TNT, Compn B, Tritonal) by increasing the wax content (Ref 35). It was found that as much as 20% wax (Wax No 10) could be emulsified in TNT by use of a NC emulsifier. The mix showed negligible separation at 100° in several hours. However, because of the questionable stability of the NC, the use of... 

American stability tests at 65.5° and 80° see Stability and instability of expls 6 E438... 

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