Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

The Use of Antioxidants to Improve Vapor Pressure Measurements on Compounds with Oxidative Instability: Methyl Oleate with tert-Butylhydroquinone

Widegren, J. A.[Jason A.], Beall, C. E.[Casey E.], Tolbert, A. E.[Audrey E.], Lovestead, T. M.[Tara M.], Bruno, T. J.[Thomas J.]
J. Chem. Eng. Data 2017, 62, 1, 539-546
ABSTRACT
The vapor pressure (psat) of methyl oleate was measured with and without the addition of 0.2 mass % of the antioxidant stabilizer tert-butylhydroquinone (TBHQ). The measurements were made by the gas saturation method with a temperature range of 303.15 343.15 K. In the absence of TBHQ, oxidative decomposition severely compromised the measurements, as evidenced by dramatic decreases in the measured psat for repeat measurements at 323.15 K. When combined with a room-temperature N2 flush of the apparatus, the addition of 0.2 mass % TBHQ limited the decomposition to insignificant levels, and resulted in repeatable measurements of psat. Simultaneous measurements on the control sample n-eicosane (C20H42) yielded values of psat that were in excellent agreement with reference correlations.
Compounds
# Formula Name
1 C19H36O2 methyl cis-9-octadecenoate
2 C20H42 eicosane
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Vapor or sublimation pressure, kPa ; Liquid
  • Temperature, K; Liquid
  • Liquid
  • Gas
  • Transpiration method
  • 9
  • POMD
  • 2
  • Vapor or sublimation pressure, kPa ; Liquid
  • Temperature, K; Liquid
  • Liquid
  • Gas
  • Transpiration method
  • 8
  • POMD
  • 2
  • Vapor or sublimation pressure, kPa ; Crystal 2
  • Temperature, K; Crystal 2
  • Crystal 2
  • Gas
  • Transpiration method
  • 1