Compatibility of polystyrene and poly(methyl methacrylate) of various molecular weights in toluene

Gel permeation chromatography has been successfully used to determine the compositions of the conjugate phases in the system of polystyrene and poly(methyl methacrylate) with toluene as solvent. Application of this method to equilibrated samples yields tie lines, binodal curves, and plait points. Polymer–polymer compatibility and the polymer–polymer interaction parameters at the plait points in this system were found to be strongly dependent on the molecular weights of the polymers.