Vapor pressure and thermophysical properties of explosive taggants

Knowledge of the vapor pressure is one of the key parameters that determine the application of detection taggants for a given explosive and useful lifetime. The objective of this work was to determine the vapor pressures and thermodynamically linked properties of selected explosive taggants, namely 2,3-dimethyl-2,3-dinitrobutane, 2-nitrotoluene, and 4-nitrotoluene. Experimental studies included vapor pressure measurements using a static method, investigation of phase behavior by differential scanning calorimetry, and measurement of condensed-phase heat capacities. On the basis of the above-mentioned data and in combination with theoretically calculated ideal-gas thermodynamic properties, the recommended vapor pressure equations for the explosive taggants in a wide temperature range were developed by the method of simultaneous correlation of vapor pressures and thermodynamically linked properties.