Shock Sensitivity Data

In the next section we will present a brief review of shock phenomena. Section III will describe exptl methods of determining shock sensitivity. Factors affecting shock sensitivity will be discussed in Section IV. Representative shock sensitivity data will be presented in Section V. Sections VI and VII will consider the mechanisms of shock initiation for homogeneous... 

In recent years a large amount of shock sensitivity data has appeared in the expls literature. To present all these data would not only be a Herculean labor but would make this article entirely unwieldy. What will be done is to give references to the most important published results with keyword description of the type of test used and the major results obtained (Table... 

Review of reactive chemicals test data for evidence of flamma-bihty charac teristics, exotherms, shock sensitivity, and other evidence of instability... 

Weiss, E.,Angew. Chem. (Int.), 1993, 32(11), 1518 Too shock sensitive to obtain crystallographic data. 

Case histories regarding reactive chemicals teach the importance of understanding the reactive properties of chemicals before working with them. The best source of data is the open literature. If data are not available, experimental testing is necessary. Data of special interest include decomposition temperatures, rate of reaction or activation energy, impact shock sensitivity, and flash point. 

Anon, SRI Prog Rept 66-2 Sensitivity Fundamentals, 39 (1966) 14) M. Van Thiel UCRL 50108 Compendium of Shock Wave Data (1966) CA 69, 99685 (1968)... 

The writer (Ref 37) used an instrumented gap test, in which 12.7 x 12.7mm cylindrical test samples were unconfined, to obtain Hugoniot data, shock sensitivity and build-up distances for RDX and other expls. For RDX the following results were obtained ... 

It seems reasonable to expect that expls that are sensitive (eg, sensitive to impact, friction, sparks, etc) will also be sensitive to shock. Generally this expectation is borne out by experience, at least in a qualitative way. Under comparable conditions PETN is certainly more shock-sensitive than TNT. and so on. An example of the parallelism in impact and shock sensitivity of four common expls is shown in the tabulation below. The comparisons are obviously qualitative in that the expls are ranked in descending order of sensitivity. It must be emphasized that reversals in sensitivity ranking can occur if comparisons are made of sensitivity data obtained under non-comparable test conditions... 

These data show that particle size exerts a small but consistent effect on shock sensitivity D. Shock Duration... 

Ref 16. Since, as will be shown below, plane-wave data for a given expl should provide a lower threshold than either the LSGT or SSGT, the above comparison strongly suggests that addition of Exon decreases the shock sensitivity of RDX... 

NOL data from Ref 32 (recomputed in Ref 42a) are summarized in Table 5. The terms SSGT and LSGT are NOL descriptions for their usual gap tests (see under Shock Sensitivity of Explosives 1 in this Vol)... 

Thermochemical data are available (Ref 2) on the heats of combustion and formation for all five isomers, on the heats of nitration from various Dinitrotoluenes for the 23,4-, 2,4,5-, and 2,3,6-isomers, and on the heats of crystn for the 2,3,4- and 2,4,5-isomers. Data are also available (Ref 1) on the shock sensitivities of all of the isomers except 2,3,6-, and on the rates of decompn at 140° of the 23,4-, 2,4,5-, and 23,5-isomers. The detonation pressure and the temp coefficient of decompn between 140 and 180° have been measured for the 2,4,5-isomer 2,3,4- and 2,4,5-TNT form addition compds ( 7r-complexes ) at 1 1 molar ratio with several polycyclic aromatic hydrocarbons (naphthalene, acenaphthene, fluorene, phenanthrene and anthracene) (Ref 2). 2,4,5-TNT forms complexes with 4-aminozaobenzene, 4-aminoacetophenone, bis (2 hydroxy ethyl) amine, and tris (2-hydroxy-ethyl) amine (Ref 1). The first two have a 1 1 molar ratio, the third 1 2, and the fourth 2 1. Upon heating, the two 4-amino compds react with replacement of the 5-nitro group, as discussed below... 

Review the reactive chemicals test data summaries for exotherms, shock sensitivity or other indicators of instability or energy release potential. 

Figure 14. Histogram of TL sensitivity values for type 5,6 ordinary chondrites. The meteorites are identified by the first three letters of their names, and the letter under the name refers to a qualitative ranking according to the intensity of shock experienced a is unshocked and f is most heavily shocked. The data along the top of the figure refer to observed TL sensitivities for samples of the Kernouve meteorite annealed for 10 h at the temperatures indicated (°C). (Reprinted with permission from Ref. 23. Copyright 1984 Pergamon Press.)...

Reactive hazard evaluations should be made on all new processes as well as existing processes on a periodic basis. There is no substitute for experience, good judgement, and good data when evaluating potential hazards. Reviews in process chemistry should include (a) reactions, (b) side reactions, (c) heat of reaction, (d) potential pressure buildup, and (e) intermediate streams. Reactive chemicals test data should be reviewed for evidence of flammability characteristics, exotherms, shock sensitivity, or other evidence of instability. Examine Planned operation of the process should be examined, especially for... 

The security data have to describe very differing properties. Shock sensitivity and thermal stability are preferred here, because the data are well accessible and only small sample amounts are needed. As a third term the detonabifity is obtained from the gap test which needs a more extensive investigation. Such data are available only for a part of the considered compounds and are reserved for the more detailed aspect of this subject. 

OSHA PEL TWA 1 mg(Fe)/m3 ACGIH TLV TWA 1 mg(Fe)/m3 DOT CLASSIFICATION 8 Label Corrosive SAFETY PROFILE Poison by ingestion and intravenous routes. Experimental reproductive effects. Corrosive. Probably an eye, skin, and mucous membrane irritant. Mutation data reported. Reacts with water to produce toxic and corrosive fumes. Catalyzes potentially explosive polymerization of ethylene oxide, chlorine + monomers (e.g., styrene). Forms shock-sensitive explosive mixtures with some metals (e.g., potassium, sodium). Violent reaction with allyl chloride. When heated to decomposition it emits highly toxic fumes of HCl. 

DOT CLASSIFICATION 6.1 Label Poison SAFETY PROFILE Poison by inhalation and intravenous routes. Moderately toxic by ingestion and subcutaneous routes. An irritant. Questionable carcinogen with experimental carcinogenic data. Flammable when exposed to heat or flame. Moderately explosive by spontaneous chemical reaction. To fight fire, use water, CO2, dry chemical. Dehalogenation by reaction with alkalies, metals, etc., will produce spontaneously explosive chloroacetylenes. Violent reaction with NaK aUoy + bromoform. Mixtures with potassium are very shock-sensitive explosives. When heated to decomposition it emits highly toxic fumes of Cl". See also CHLORINATED HYDROCARBONS, ALIPHATIC. 

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