Vapor Pressure of Hexamethylene Triperoxide Diamine (HTMD) Determined with Secondary Electrospray Ionization Mass Spectrometry
Journal Article - Open Access
MIT Lincoln Laboratory Lexington United States
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A dynamic method for vapor pressure measurement was developed and used to derive the vapor pressure curve of the peroxide-based explosive hexamethylene triperoxide diamine HMTD over the temperature range of 301 353K 28-80C. The method utilizes a controlled flow of explosive vapor from solid-phase explosive dispersed on an inert solid support and presents it to an ambient-pressure ionization mass spectrometer equipped with a secondary-electrospray-ionization SESI source. The sensitivity of this system enables direct detection of HMTD vapor via an intact molecular ion in real-time at temperatures near 298K. Direct detection of HMTD vapor at near-ambient temperatures is necessary when characterizing the thermochemical properties of HMTD because its high thermal ability precludes analysis by most conventional vapor pressure measurement methods. The temperature dependence of HMTD vapor was measured using this approach and a Clausius-Clapeyron plot of LnPPa vs. 1TKyielded a straight line with the expression LnPPa -11245440 1TK 26.21 error limits are the standard error of the regression analysis. From this equation the sublimation enthalpy of HMTD was estimated to be 93.53 kJmol and the extrapolated vapor pressure at 293.15K is lnPPa -121.8or 52 parts-per-trillion by volume.
- Nuclear Physics and Elementary Particle Physics