(352l) Volumetric, Acoustic, Viscosimetric and Spectroscopic Properties of Binary Liquid Solutions Containing Gamma-Valerolactone (GVL) and Alcohols

Substances derived from biomass have called attention of scientific and industrial fields, once these compounds represent a group of renewable solvents, whose physicochemical properties present great potential for applications in several areas of science and in the industry, namely in biorefineries [1]. Therefore, thermodynamic properties of systems containing such liquids is of practical interest, as experimental data can be used in modeling to improve processes or yet to develop and verify new models and solution theories, which have shown their complexity [2].

This project aims at studying thermodynamic and spectroscopic properties of binary liquid systems constituted of a biomass-derived solvent, gamma-valerolactone (GVL), and alcohols. For this purpose, original values of density and speed of sound were obtained by an analyzer manufactured by Anton Paar (model DSA 5000) while dynamic viscosity was measured by a rotational viscometer from Anton Paar (model SVM 3000) for the four following systems: GVL + ethanol, or + 1-propanol, or + 1-butanol, or + 1-pentanol in the whole composition range, at five temperatures T = (293.15 -313.15) K and under ambient pressure p = 92.3 kPa.

From experimental results, it was possible to calculate volumetric properties such as excess molar volume, acoustic property as deviation in isentropic compressibility, viscosimetric property as deviation in viscosity and excess Gibbs energy of viscous flow. To complete the thermodynamic discussion, both nuclear magnetic resonance (Avance III 600 HD Bruker) of hydrogen and of carbon as well as Fourier transform infrared with attenuated total reflectance spectroscopy (model 6700) have been performed.

Since both GVL and alcohols are polar solvents and also have electron acceptor and donor sites, respectively, they present peculiar interactions, especially chemical ones such as hydrogen bonding through oxygen and hydrogen atoms. For the systems studied, all thermodynamic properties presented negative values under every condition, except excess volumes, which experienced positive and negative values.

[1] G. Strappaveccia, L. Luciani, E. Bartollini, et al., Green Chem., 17 (2015), 1071-1076.

[2] N. Deenadayalu, I. Bahadur, T. Hofman, J. Chem. Eng. Data, 55 (2010), 2636-2642.