Vaporization behavior of an alkyl diphenyl ether and a commercial lubricant

The equilibrium vapor pressure as a function of temperature for an alkyl diphenyl ether with a vaporization coefficient significantly smaller than unity was characterized using the combined Langmuir free evaporation and mass loss Knudsen effusion technique. Results are compared using different cell designs and discrepancies, difficulties, and complications are discussed. The enthalpy and entropy of vaporization are estimated using the average temperature of the measurements.