Microwave dielectric spectroscopy of pure and mixed aromatic ester solvents

Abstract

The structure and dynamics of pure and mixed liquid aromatic esters is studied through microwave dielectric relaxation spectroscopy in the 200 MHz -20 GHz frequency range. Methyl, ethyl, propyl and butyl benzoate were studied at 298.15 K to infer the alkylic chain length effect on solvents properties showing that the relaxational behaviour for the four esters is properly described with a single Debye type function for the considered range. Methylbenzoate behaviour was also analyzed in the 278.15 -358.15 K temperature range to study the temperature effect on their properties. Experiments on phenyl acetate were carried out to analyze the effect of aromatic ring position on fluid structure. We have also considered the properties at 298.15 K of different methylbenzoate containing mixed fluids with n-hexane, cyclohexane, 1-chlorohexane, 1-hexanol, hexanoic acid and diisopropyl ether to study the effect of different functional groups on fluid structure upon mixing. All the binary mixtures studied are properly described using a bimodal Debye process in the whole composition range. Data are analyzed in terms of the proposed different species present in the fluids and their evolution with composition for mixtures, and with temperature and chain length for pure esters.

Compressed liquid density measurements for {methylbenzoate+(cyclohexane or 1-hexanol)} binary systems

“…This work reports results of the ongoing research carried out by our research group on binary and ternary methyl benzoate-containing mixtures [11][12][13][14][15][16][17][18], including thermophysical properties study for binary mixtures of methyl benzoate and organic solvents, which are provided with six carbon atoms but different structure and functional groups, as a function of pressure and temperature [19]. Thus, we report the experimental densities and their derived properties for the binary mixtures of MB/1-hexanol and MB/cyclohexane, in the whole composition range from (278.15 to 358.15) K and pressures up to 60 MPa.…”