Musso, E.; Tesser, R.; Basile, G.; Di Serio, M. Santacesaria, E.
Journal of Fluorine Chemistry 103 (2000) 41-51
An extended Flory-Huggins model has been developed and used to interpret liquid-liquid phase diagrams related to binary mixtures of CFC-lubricating oil for which miscibility gaps of UCST, LCST and hourglass type are present. Some liquid-liquid equilibrium measurements have been carried out for the fluorinated compounds R134a, R125, R143a, and R32 in mixtures with polyester-based lubricating oils (PES), pentaerythritol tetraheptanoate (PTE) and trimethylolpropane triheptanoate (TTE). The extended Flory-Huggins model has been applied in the simultaneous description of the liquid-liquid and vapor-liquid phase equilibrium using the same set of adjustable parameters. On the basis of the results obtained in fitting binary systems, a predictive approach has been developed for the description of a miscibility gap related to a mixture formed by two or more halogenated compounds with a lubricating oil