Análisis experimental y teórico de diversas propiedades termofísicas de sistemas ternarios compuestos de glimes alcoholes y DI-N-Butiléter, y de sus componentes binarios

Abstract

En este trabajo se realiza la caracterización termofísica de las mezclas líquidas ternarias formadas por Etéres Dimetílicos de Polietilenglicoles (CH3-O-(CH2- CH2-O)n-CH3), comúnmente llamados Glimes, que contienen uno, dos y tres grupos oxietileno (Monoglime, Diglime y Triglime), 1-Alcoholes (Etanol, 1- Pentanol y 1-Octanol) y Di-n-butiléter, así como las de las binarias constituyentes, basada en la determinación experimental precisa de propiedades termodinámicas y de transporte a diferentes temperaturas. En concreto, se determinan las densidades y viscosidades cinemáticas, a la presión atmosférica normal, de los sistemas binarios a 283.15, 293.15, 303.15 y 313.15 K y las de los sistemas ternarios a 303.15 K

This work is an approach to the thermophysical characterization of the ternary liquid mixtures of Polyethylene Glycol Dimethyl Ethers (CH3-O-(CH2-CH2-O)nCH3), also called Glymes ( Monoglyme, Diglyme and Triglyme) with Alkan-1-ol (Ethanol, Pentan-1-ol and Octan-1-ol) and Di-n-butyl Ether, and their binary mixtures, which is based on the experimental determination of transport and thermodynamic properties at different temperatures. The density and the kinematic viscosity of the binary systems were determined at 283.15, 293.15, 303.15 and 313.15 K and at the atmospheric pressure and, for the ternary systems, at 303.15K. The excess molar volumes of the bicomponent systems, that were obtained from density measurements, were adjusted by polynomical functions which depend on the mixture composition and temperature. This is useful to achieve other interesting volumetric properties in the central temperature of the studied interval. The excess molar volumes of binary and ternary mixtures were compared with those provided by the group contribution model proposed by Nitta and al., through the use of parameters stated in literature. The data of dynamic and kinematic viscosity of the binary systems were also used to prove the validity of several specific empirical and semiempirical models proposed in literature. Excess volumes and viscosity deviations values of the ternary systems were compared to the corresponding results providing from symmetrical and asymmetrical models of prediction based on experimental results of the binary systems under study. Due to their interest for serveral fields of Physical Chemistry and Engineering, the experimental results undergo analysis in order to reveal an interpretation of the possible phenomena occurred during the mixture process and their effects, taking into account the existing unbalance between the weakening of the actual interaction in pure components (homo-molecular) of the mixtures and the formation of new interactions among them (hetero-molecular), these being the energy phenomena operating during the mixture process. Different structural effects, such as the packing of the mixture related to the pure components structure, become as well fundamental when reaching the meaning of phenomena occurring during the mixture process.