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

Study of the Effect of Pressure on Melting Behavior of Saturated Fatty Acids in Liquid or Supercritical Carbon Dioxide

Trivedi, V.[Vivek], Bhomia, R.[Ruchir], Mitchell, J. C.[John C], Coleman, N. J.[Nichola J], Douroumis, D.[Dennis], Snowden, M. J.[Martin J]
J. Chem. Eng. Data 2013, 58, 6, 1861-1866
ABSTRACT
The melting point depression of saturated fatty acids (C12 C18) was investigated in liquid or supercritical carbon dioxide. The pressure and temperature melting point ranges were determined for each excipient in liquid or supercritical CO2. Additionally, the effect of pressure on the melting point of fatty acids was also more closely studied in the (7.0 to 50.0) MPa range. Untreated and CO2-treated samples were analyzed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). A melting point depression in the range (10.8 to 19.5) K was observed for the fatty acids studied in this work. The melting behavior of fatty acids in CO2 was found to be dependent on pressure and carbon chain length. Melting temperature curves for each of the fatty acids in CO2 exhibited a minimum as a function of pressure. Analysis by DSC and XRD indicated that CO2 treatment had no impact on the morphological or crystallographic properties of these excipients under the selected experimental conditions.
Compounds
# Formula Name
1 C18H36O2 octadecanoic acid
2 C16H32O2 hexadecanoic acid
3 C14H28O2 tetradecanoic acid
4 C12H24O2 dodecanoic acid
5 CO2 carbon dioxide
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
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 2
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 3
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 4
  • Normal melting temperature, K ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • DTA
  • 1
  • POMD
  • 1
  • 5
  • Triple point temperature, K ; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 1
  • Gas
  • DTA
  • 8
  • POMD
  • 2
  • 5
  • Triple point temperature, K ; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 2
  • Gas
  • DTA
  • 8
  • POMD
  • 5
  • 3
  • Triple point temperature, K ; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 3
  • Gas
  • DTA
  • 8