Design of Novel Energetic Materials

As we have already discussed above, secondary explosives (or high explosives) are homogeneous substances which can either be covalent or ionic. However, in both cases it is important that the oxidizer and fuel are combined within one molecule (i.e. in one covalent molecule or in one ionic formula unit). For example, this is the case for TNT, in which the three nitro groups correspond to the oxidizer, and the C—H backbone acts as the fuel. Such molecules belong to the oxidation of the carbon backbone group of substances (Tab. 9.1). 

Principally, members of both of the above mentioned classes of compounds (oxidation of the molecule back-bone ring and cage strain) can be exothermic or endothermic compounds. An example of the former is TNT with Af//° = -295.5 kJ kg , while RDX shows a positive standard enthalpy of formation of Af/f° = +299.7 kJkg-.  

A third class of highly energetic materials is always endothermic and is called nitrogen-rich molecules (Tab. 9.1). The reasons why nitrogen-rich molecules are par- 

If we first consider the bond energies for typical C—C, N—N and 0—0 single, double and triple bonds, we can see that the bond strength increases from single to double to triple bonds (which is unsurprising) (Fig. 9.1). 

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