Thermodynamics of 1-alkanol + cyclic ether mixtures

Abstract

1-Alkanol + cyclic ether mixtures have been investigated in terms of the DISQUAC and ERAS models and using the concentration–concentration structure factor ( S CC(0)). The corresponding interaction parameters are reported. DISQUAC interaction parameters for the systems 1-alkanol + 1,7,10,13,16-hexaoxacyclooctadecane (18CE) and methanol + 1,3,5-trioxane are also given. DISQUAC correctly describes a whole set of thermodynamic properties: vapor–liquid equilibria, VLE, molar excess enthalpies, H E, solid–liquid equilibria, SLE, and S CC(0) of the binary systems. H E of 1-alkanol + cyclic ether + alkane mixtures are fairly well represented by DISQUAC using binary parameters only. ERAS provides a semiquantitative description of the investigated mixtures due to the fact that main contribution to their thermodynamic properties is usually the physical one. 1-Alkanol + cyclic ether systems are characterized by dipolar interactions and homocoordination. Interactions between unlike molecules are stronger in mixtures with tetrahydrofuran (THF) or 1,3-dioxolane, when are compared with those present in solutions with tetrahydropyran (THP) or 1,4-dioxane. The DISQUAC interaction parameters underline that proximity effects are more relevant in systems with 1,3-dioxolane or 1,3,5-trioxane. THP, 1,4-dioxane and 18CE form a homologous series in the framework of DISQUAC.