Ambient Volatility of DMMP

A novel experimental apparatus and procedures have been developed and implemented to measure the volatility of a chemical warfare agent simulant as a function of ambient temperature and water vapor partial pressure. Initial data have been measured for dimethyl methylphosphonate (DMMP) to validate the methodology. The results presented herein reveal a significant volatility suppression for DMMP, increasing as the relative humidity increases. Deviation from ideal behavior as described by Raoult’s law has been quantified. The maximum deviation from ideality occurs at water partial pressures near 500 Pa. An empirical model has been developed to enable interpolation and limited extrapolation of the data to higher water partial pressures as might be found in compressed-air regenerative filtration applications.