Published in

Elsevier, Fluid Phase Equilibria, (366), p. 88-98

DOI: 10.1016/j.fluid.2014.01.004

Links

Tools

Export citation

Search in Google Scholar

On the solid–liquid equilibrium of binary mixtures of fatty alcohols and fatty acids

This paper is available in a repository.
This paper is available in a repository.

Full text: Download

Green circle
Preprint: archiving allowed
Red circle
Postprint: archiving forbidden
Red circle
Published version: archiving forbidden
Data provided by SHERPA/RoMEO

Abstract

Fatty alcohols and fatty acids are used in the cosmetic, pharmaceutical and food industries as surfactants. They are also considered phase change materials for thermal storage processes. Information on their thermal properties is required for optimizing production processes as well as for improving their industrial and home use. In the present study, the solid-liquid phase diagrams of three binary systems of 1-tetradecanol + dodecanoic acid, 1-hexadecanol + tetradecanoic acid and 1-octadecanol + hexadecanoic acid were determined by differential scanning calorimetry. The phase-transition phenomena were further investigated by optical micrographs and X-ray diffraction patterns. The experimental data showed that the systems present eutectic transitions and some of them exhibit partial solid phase miscibility. The liquid phase activity coefficients were calculated by Margules 2 and 3-suffix and by UNIFAC and UNIFAC-Dortmund methods. The modeling approach resulted in an accurate prediction, with average absolute deviations from experimental data lower than 1.16 K. The values of excess Gibbs free energy present an unusual behavior, with positive deviations at very low alcohol concentrations and negative ones at high concentrations of this component. This occurs due to changes in the H-bonding interactions along the concentration range of the mixture.