Determination of Vapor Liquid Equilibrium from the Kovats Retention Index on Dimethylsilicone using the Wilson Mixing Model

Abstract

Non‐ideal mixing in a dimethylsilicone stationary phase is modeled according to the Wilson activity coefficient. Pure liquid vapor pressures of alkylated compound series are calculated from capillary GLC retention with the functional group heat of solution in a polymer solvent. The new method uses the Kovats index, molar mass, and functional group to determine the bubble line of a compound. Boiling points at reduced and normal pressure are compared to literature values of 194 gasoline components. An unlike molecular pair interaction parameter is derived, using only bubble line data of the pure liquids. Binary phase diagrams are constructed and compared to vapor liquid equilibrium data.

Determination of Ambient Temperature Vapor Pressures and Vaporization Enthalpies of Branched Ethers

“…The Kovat's indices are generally specified by the choice of the stationary phase of the GC column. As a rule, the isothermal Kovat's indices are only slightly dependent on the GC oven temperature. , Thus, the J x method seemingly does not have restrictions associated with the choice of the temperature interval for investigation, as the original Chickos method 17 and any set of the homologues available from the literature could be used for a linear correlation with the reliable data on vaporization enthalpies. But the question arises concerning if there is any correlation between Kovat's indices and vaporization enthalpy.…”