Excluded-Volume Effects in Dilute Polymer Solutions. V. Butyl Rubber in Various Solvents

It is a fundamental requirement of the two-parameter theory of linear homopolymers in dilute solution that the expansion factor α, and the interpenetration function Ψ depend only on the excluded-volume parameter z and that these functions are universal in the sense that their forms are independent of the chemical nature of the polymer and solvent as well as of the temperature. It follows immediately from the above requirement that the values of Ψ for different combinations of polymer, solvent, and temperature should form a single composite curve when plotted against αs.