Global phase diagrams for polymer-solvent mixtures within the modified Tompa model

We obtained the global phase diagrams (GPDs) forpolymer-solvent mixtures by using the modified Tompa model. We construct theGriffiths shield regions (GSRs), the zones that interaction energies are almostequal, are obtained on the GPDs. We examine and discuss the influences ofvarious segment sizes of polymer molecules on the GPDs and the GSRs. We observethat the GPDs are symmetrical around ζ=0 for the equal-size segments of polymermolecules and the break down in the symmetric features of the GPDs rises asdifferences of segments of polymer molecules rise. Moreover, the types IV*, VIand VII phase behaviors are seen for differences of segments of polymermolecules in addition to the types I, I-A, II, II-A, III, III-HA, IV, V and V-Aaccording to the van Konynenburg and Scott binary fluid phase behaviorclassification. It is also observed that differences in the polymermolecules segments effect on the sizes of the phase type domains and the typesof phase behaviors.