A Dielectric Study of Intermolecular Interactions of 1,3-Propanediol with 1-Octanol and 2-Ethyl-1-hexanol at Various Temperatures

This study reports the experimental permittivity data for the polar binary systems of 1,3-propanediol with two primary octanol isomers (1-octanol and 2-ethyl-1-hexanol) in a range of compositions at T = 298.15, 308.15, and 318.15 K and p = 101.3 ± 0.4 kPa. The main structural difference between these two isomers is that the first isomer is a straight and the latter is a branched primary alcohol. The Kirkwood-Frohlich equation was used to evaluate the effective dipole moments of the pure substances and their binary mixtures. In order to obtain information about intermolecular interactions, the excess parameters such as the excess permittivity and the excess Helmholtz energy were evaluated. The data were interpreted in terms of hetero interactions and structure of the investigated binary mixtures.