Re-examination and symmetrization of the adjustable parameters of the ERAS model: Review on its formulation and application

This paper presents an intensive revision of the application of the extended real association solution (ERAS) model for binary mixtures containing one or both self-associating compounds. We suggest new definitions for the complexation constant KAB and for the Flory’s parameter XAB, which involve a symmetrization of the model with respect to the change A↔B in addition to endow these parameters with a clearer physical meaning. The new expresions for KAB and XAB also imply an extension of the model for application to any binary mixture exhibiting cross-association regardless of the relative degree of self-association of the components. A critical review on the formulation and application of the model is performed in order to clarify several disagreeing points in papers related to this matter.