Dynamical measurement of saturation vapor pressures below and above room temperature

Abstract

We report on the implementation of a dynamical method for the determination -- in an extended temperature range around room temperature -- of the saturation vapor pressure and enthalpy of vaporization of low-volatility liquid substances. The method relies on isolating a \textit{precooled} substance in a heated chamber under static vacuum conditions and monitoring the chamber pressure as the sample slowly thermalizes to the chamber temperature. We apply the method to four reference substances -- diethyl phthalate, 1-decanol, 1-heptanol, and 1-hexanol -- and provide accurate data for their saturation vapor pressure and enthalpy of vaporization in the range from $-10$ to $35^\circ$C.