Abstract
The polytropic equation, together with the detonation relations, provides practicable values for all the quantities characterizing the detonation products of solid, high explosives apart from the temperature. Its application, however, is restricted to material at absolute zero, that is to solids possessing purely potential energy. Thus polytropic detonation products have the characteristics of solids although their state of aggregation is gaseous.
In fact the polytropic equation can be derived by assuming a solid under an internal, expansive pressure sufficient to break all atomic bonds. In terms of the Debye theory this represents an approximation which is valid in the absence of the thermal energy contribution from atomic vibrations. This requirement is satisfied by the detonation products of solid explosives of sufficiently high density since their heat of detonation is completely absorbed by the breakage of atomic bonds or the sublimation of the atomic lattice.
The sublimation process in the course of the reaction also allows the ChapmanβJouguet temperature of the detonation products to be determined from the equilibrium between the phases. In addition the fracture theory provides material data which assign a metallic character to the polytropic detonation products and indicate that they form a conducting plasma.