Primary explosives molecular groups

Classifying explosives by the presence of certain molecular groups does not give any information on the performance of the explosive. A far better way of classification is by performance and uses. Using this classification, explosives can be divided into three classes (i) primary explosives, (ii) secondary explosives, and (iii) propellants as shown in Figure 2.1. 

Detonation, as described earlier, is a process where upon a matrix of uniform particles of gas and solid forms a pressure wave. The pressure wave is what causes the bulk of destruction. However, it should be noted that detonation is a completely different process then deflagration and combustion. As previously stated, compounds that detonate must poses certain functional groups. These functional groups are initiated by molecular shocks generated by blasting caps, detonators, and/or boosters. Of coarse not all explosives need to be initiated by blasting caps, detonators, and/or boosters for example, primary explosives (which you will learn much about shortly) can be detonated under relatively easy means by sparks, heat, friction, percussion, fire, and shock. 

By means of analogous approach as in the case of relationships in Fig. 1 we have studied mutual relationships between the characteristics of detonation and NMR chemical shifts of nitramines [26]. In contrast to the above-mentioned Fig. 1, the characteristics (i.e. heat of explosion or square of detonation velocity, D ) correlate with the N NMR chemical shifts, of nitro-group nitrogen atoms. Corresponding relationships for square of detonation velocity, D, are presented in Fig. 6. Here the if values correlate with the Sn values of the most reactive nitro groups [26]. Therefrom it follows that, that the primary fission of nitramine molecule is the same as that in the case of initiation by impact (see Scheme 1). Again this fact perfectly agrees with the conclusions drawn by Kohno et al. [27] fi-om the molecular dynamics study of impact and shock reactivity of nitramines. 

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