Excluded volume in ternary polymer systems

Abstract

Several studies have focused on developing a theory of the excluded volume effect in polymer solutions in good accord with experimental data. There are very few expressions for the interpenetration factor, Ψ, which can be chosen for a given theory of the expansion factor α³_s. The combination of Kurata–Yamakawa theory for Ψ with Yamakawa–Tanaka theory for α is in good accord with experimental data on binary polymer systems. However, no self-consistent combination of theories can be chosen to describe the behaviour in ternary polymer systems. A modified expression for the interpenetration factor has been developed for ternary polymer systems. It depends on intrinsic viscosities and on the Kurata–Yamakawa binary interpenetration factor. Good qualitative agreement has been attained by comparing the modified (Ψ, α) plot with experimental data on reported ternary systems. A useful application is the theoretical calculation of second virial coefficients.