Phase Equilibria of Quasi-Ternary Systems Consisting of Multicomponent Polymers 1 and 2 in a Single Solvent I. Spinodal Curve and Critical Solution Point

Abstract

Theoretical equations of spinodal and neutral equilibrium conditions were derived, based on modified Flory–Huggins theory and without further approximation, for quasi-ternary solutions consisting of a multicomponent polymer 1/multicomponent polymer 2/single solvent. Numerous and systematic computer experiments clarified the effects of three thermodynamic interaction parameters between solvent–polymer 1 (χ01), solvent-polymer 2 (χ02), and polymer 1-polymer 2 (χ12), the weight average degrees of polymerization of original polymers 1 and 2 (Xw0 and Yw0) and the breadth of the molecular weight distribution of original polymers (Xw0/Xn0 and Yw0/Yn0; Xn0 and Yn0 are the number-average degree of polymerization, X and Y, of the original polymers) on the spinodal curve and critical solution points. Here, the possible compositional dependence of three χ parameters were not considered.