Revision of the Group-Contribution-Flory Equation of State for Phase Equilibria Calculations in Mixtures with Polymers. 2. Prediction of Liquid-Liquid Equilibria for Polymer Solutions

Thermodynamics of paint‐related systems with engineering models

“…However, as shown by many researchers, predictive models, such as Entropic-FV and GC-Flory, yield only qualitatively satisfactory results for LLE, even for moderately complicated polymer solutions Ž . Kontogeorgis et al, 1995;Saraiva et al, 1995 . The same models are more satisfactory for VLE and infinite dilution activity coefficients, as shown for paint systems in the previous section. Since a yesrno answer is often adequate, it is highly advantageous to employ rules of thumb for solvent selection based exclusively on the knowledge of the solvent activity coefficient at infinite dilution.…”

“…Many reviews of the numerous thermodynamic models for systems containing polymers have been given in the literature ŽGoydan et al, 1989;Fried et al, 1992;Danner and High, 1993;Bogdanic and Fredenslund, 1995;Condo and Radosz, . 1996;Lee and Danner, 1997;Bokis et al, 1999 , showing that the accuracy depends on the type of equilibrium and system to be considered.…”

A continuous polydisperse thermodynamic algorithm for a modified flory-Huggins model: The (polystyrene + nitroethane) example

“…Following the classification proposed by Saraiva, 9,20 two main different approaches can be considered: (1) qualitative and/or semiquantitative descriptions of LLE in terms of polymer solubility, where the main purpose is to predict whether or not a polymer is soluble in a certain solvent (or mixture of solvents) at certain conditions; (2) quantitative and qualitative descriptions of LLE, attempting to establish dependencies of LLE with temperature, composition, and pressure.…”

Miscibility of polymer blends with engineering models

“…Thus, it seems that the GC-Flory EOS cannot predict the upper critical solution behavior for polymer blends. Although it has been proved that the GC-Flory is an excellent model for calculating vapor-liquid equilibria, and reasonably good for predicting liquid-liquid equilibria in polymer solutions (Bogdanic and Fredenslund, 1994;Saraiva et al, 1995b), the current results for polymer blends do not justify the expectations that one might have from a complex thermodynamic model.…”

“…Typically, the difference between the experimental and the predicted lower critical solution temperature (LCST) is around 200°C. These results are in sharp contrast to the relative success of the GC-Flory model in predicting vapor-liquid and liquid-liquid equilibria for polymer solutions (Bogdanic and Fredenslund, 1994;Saraiva et al, 1995b). The problems of the GC-Flory EOS in predicting phase equilibria for polymer blends demonstrate the difficulties that some complex models may reveal when applied to complex systems.…”