Thermodynamic Properties of Energetic Plasticizers: Experimental Vapor Pressures of Methyl-, Ethyl-, and Butyl-Nitroxyethyl Nitramines

Abstract

In this work, experimental vapor pressures of the commonly used energetic plasticizers methyl-NENA, ethyl-NENA, and butyl-NENA were measured for the first time with a transpiration method. The p−T fitting equations and the corresponding molar enthalpies of phase transitions at 298.15 K are reported: the molar enthalpies of sublimation and vaporization of methyl-NENA were measured to be 104.5 ± 0.9 and 82.0 ± 1.1 kJ•mol −1 , respectively. The consistency of these results was examined by the differential scanning calorimetry experiment, which yielded the molar enthalpy of fusion at 298.15 K to be 23.8 ± 0.3 kJ•mol −1 . The molar enthalpies of vaporization at 298.15 K for ethyl-and butyl-NENAs were derived to be 79.8 ± 0.4 and 85.9 ± 0.5 kJ•mol −1 , respectively. The p−T fitting equations were extrapolated at 298.15 K, and the corresponding results were reported in this work.

Crystal Structures of the Commonly Used Plasticizers Ethylene Glycol Dinitrate, Diethylene Glycol Dinitrate, and Triethylene Glycol Dinitrate─Characterization and Discussion of Their Structural Behavior

“…Examination of the determined enthalpies of both this work and the literature, as well as visualization of the p–T data sets, revealed rough agreement with the literature values. The marginal deviations of the literature values from our results are plausible by considering the limits of the piston manometer and the insufficient number of data points in comparison with the versatile evaluated transpiration method in this work. ,, …”

“…However, since both literature sources show deficits, in the data set of Vacek, the determination of the fit function cannot be reconstructed and experimental data points are not given at all, and in the data set of Crater, it can be clearly recognized that neither the described linear behavior is present nor the reproduction of the data points has taken place to a satisfactory extent. In contrast, our method has been evaluated several times, and in previous work, the thermochemical properties of well-characterized compounds have been reliably reproduced. , …”

“…The results are presented in Table . The exact method description can be found elsewhere, and the VO-GC/MS parameters can be found in the Supporting Information. , …”

“…EDGN: The vaporization behavior of EGDN was measured by Härtel in the temperature range of 274.1 to 318.2 K . The values of the molar enthalpy of vaporization ((65.1 ± 0.3) kJ mol –1 ) and extrapolated vapor pressure at a reference temperature of 298.15 K (12.1 Pa) were determined.…”

“…The exact method description can be found elsewhere, and the VO-GC/MS parameters can be found in the Supporting Information. 31,32 EDGN: The vaporization behavior of EGDN was measured by Hartel in the temperature range of 274.1 to 318.2 K. 31 The values of the molar enthalpy of vaporization ((65.1 ± 0.3) kJ mol −1 ) and extrapolated vapor pressure at a reference temperature of 298.15 K (12.1 Pa) were determined. A detailed consideration of the literature values was carried out by Hartel, to which reference is drawn here.…”