Generalized polymer-solvent phase diagram

Analytical relations for the spinodal and binodal in the phase diagram of a polymer solution both with and without reference to the concentration dependence of the parameter ϵ have been obtained. A method is proposed for constructing a generalized phase diagram. The generalized phase diagram in the proposed coordinates is common to a wide class of flexible chain polymers of varied MW in different solvents. The calculated relations are compared with the experimental data for PS solutions in different solvents, PIB and PE. Good agreement of the analytical relations and the experimental results is demonstrated.