(257x) Viscosimetric Properties of Binary Liquid Mixtures Containing Acetonitrile and Glycols at Different Temperatures

This study aims the experimental determination of viscosity measurements of binary liquid solutions containing acetonitrile + polyethylene glycol 200 (PEG 200) and + polyethylene glycol 300 (PEG 300), over the entire composition range, at different temperatures and at atmospheric pressure. The experimental data were used to calculate viscosity deviation (Δη), and excess Gibbs energy of activation (ΔG^*E). The results were adjusted by a polynomial Redlich-Kister type. The experimental viscosity results will be used to test the applicability of the empirical equations proposed by Grunberg-Nissan, Hind-McLaughlin, Katti-Chaudhary and Heric-Brewer.

          In industrial applications, knowledge of the experimental data in viscosity and therefore its derivatives properties of liquid systems as a function of composition and temperature are important due to the fact that the viscosity is a property frequently used in designs of industrial processes. These properties are required in many calculations in Chemical Engineering involving fluid flow, heat and mass transfer. Systematic studies and the knowledge of the dependence of these properties as a function of composition and temperature of the mixture are of great importance from a theoretical point of view, since they allow the understanding of possible intermolecular interactions present in the system.

          In the last decade, major efforts have been made to use environmentally friendly solvents in organic synthesis, biochemical engineering as well as manufacturing and service industry. Polyethylene glycols are considered non-toxic and biodegradable polymers. Their structures enable these compounds to be donors and acceptors of protons. PEGs are also known as an additive in the food industry and are used for many biological and biomedical applications in aqueous solutions and in aqueous systems with biological macromolecules.

          Acetonitrile is already widely used as a reaction solvent for the production of antibiotics. It is also one of the most used solvents in the butadiene extraction. Once highly purified, it can be used as a solvent in high performance liquid chromatography.

For the studied systems, viscosity deviation was negative over the entire composition range and it becomes less negative when temperature increases. The values of excess Gibbs energy of activation were positive over the entire composition range and it becomes less positive when temperature increases. For the analysis of Gibbs energy, the binary system with PEG 300 has energy values higher than the results with PEG 200.