POLYAZEOTROPY IN BINARY-SYSTEMS .2. ASSOCIATION EFFECTS

Polyazeotropy in binary systems is a singular case of vapor-liquid equ ilibrium where at a given temperature or pressure various azeotropes o f alternating deviations from ideality are observed. These deviations are generally caused by liquid-phase nonidealities, but in associated systems and even at low pressures, the vapor-phase nonidealities are r emarkable. Associated systems are analyzed using chemical theory, wher e associated species are considered to be products of polymerization r eactions; in those systems, azeotropy can be achieved without the usua l requirement of equal composition in the phases. The purpose of this work is to show how the combination of nonidealities in both liquid an d vapor phases can induce polyazeotropy and to establish its thermodyn amical conditions.