Sensitivity of solid explosives

Price, D., Jaffe, J. und Robertson, G. E. Shock Sensitivity of Solid Explosives and Propellants, XXXVI. Int. Kongrefi f. Industrielle Chemie, Brussel 1966Lee, J. H., Knystautas, R. und Bach, G. G. Theory of Explosion, McGill University Press, Montreal 1969... 

Donna Price et al, Shock Sensitivity of Solid Explosives and Propellants , paper presented to be published in Proc36thCongr sIn-ternational de Chimie Industrie lies, Belgium, Sept 1966 17) Donna Price, Contrasting... 

The experimental finding of Wohler and Wenzelberg (VoL I. p. 3) gives a general estimation of the sensitivity of nitroaromatic explosives to impact as a function of the character and number of substituents to the benzene ring. On the other hand T. Urbadski [36] expressed the view in 1933 that the sensitivity of solid explosives to impact is a complicated function of a few factors, among which the most important are ... 

It was known that the inclusion or addition of grit (a hard inert substance) enhances the impact sensitivity of solid explosives, especially the primary explosives, long before any systematic effort was made to determine all the effects. 

As indicated, the thermal sensitivity of solid explosives is studied by two basic methods. The first heats a sample to give a constant rate of temperature rise, the explosion temperature being taken as the temperature at the time of ex-... 

Fia 6 Effect of A on shock sensitivity of various explosives. NQ-f is low-bulk-density nitroguanidine with hollow-needle crystals of about 5 n diam X 60-65 it long. NQ-h is the high-bulk-density material made up of solid particles of about GO-65 n diam. DATB, TNT, and Tetryl are, respectively, dia-minotrinitrobenzene, trinitrotoluene and trinitro-phenylmethylnitramine. RDX is cyclotrimethyl-enetrinitramine which contains 2.5% lubricant. Measurements were carried out with a standardized test (Ref 16) in which a 3.65-cm-diam test explosive confined in 0.55-cm-thick steel is the acceptor and polymethyl methacrylate is the gap material MGl = NCro filt ro uasiM i ... 

Liq oxygen is used with an intimate mixture of a main mass of a solid combustible material such as lamp black together with starch in a proportion materially to reduce the sensitivity of the explosive (eg, 10—30% of 300 mesh starch). H. Sauvage, USP 2076279 (1937)... 

This test seeks to evaluate the sensitivity of solid substances to impact. For these purposes, the 50% explosion height (where the explosion occurs at 50% probability) is measured by dropping a steel ball onto a standard mixture made of some standard substance and a flammable substance. The sample is judged "go" (for explosion) or "no go" (for no response) at 50% probability by dropping the same steel ball onto a sample mixture made with sample in question and a flammable substance from the... 

The lack of a quantitative understanding of the mechanism of initiation of solid explosives, as reflected in the discussions of Chapters 6-9 of Volume 1, led to the development of empirical tests to relate the sensitivities of different materials to significant stimuli, such as shock, impact, friction, electric discharge, and heat. 

Besides the hardness, the size of the grit particles is important, and particles larger than 20 /zm diam are more effective. However, particles of diamond as small as 0.5 /zm still had a sensitizing effect on a number of solid explosives. Particles as small as this are present in most explosives, no matter how carefully they are prepared. 

A considerable amount of experimental work has been done on the initiation of solid explosives by low-velocity impact (a few m/sec). Although the data for various situations are valuable as regards the practical use of the explosives, understanding of impact initiation is still far from clear. Ideally, if the various physical and chemical parameters of a reactive material were known, it would be possible to predict the sensitivity of the material to any mechanical stimulus. However, this ideal is far from being achieved, and at present the only reliable approach is to conduct experiments. 

In spite of intensive research for many decades, the theory of combustion and explosion has not been able to explain the phenomenom of sensitivity of solid crystalline explosives to shock and fiiction. The phenomena is well known, and in practice often used (for the ignition of solid explosives by shock or by a short dynamical action), but is still waiting for a theoretical explanation. The thermal approach was used to address the problem mechanical action (shock, fiiction) is transformed into... 

Explosive solids can be detonated by heat, mechanical impact, friction, or electrical spark or discharge. The sensitivity of an explosive is the effect of the stimulus on its spontaneous detonation ... 

Solid diazonium salts are very sensitive to shock when perfectly dry and detonate violently upon gentle heating they are, therefore, of little value for preparative work. Happily, most of the useful reactions of diazonium compounds can be carried out with the readily-acoeasible aqueous solutions, so that the solid (explosive) diazonium salts are rarely requir. ... 

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