Moderately concentrated solutions of polystyrene. I. Viscosity as a function of concentration, temperature, and molecular weight

Abstract

AbstractData on the viscosity η of moderately concentrated solutions of polystyrene are reported. Several solvents were investigated, including cyclopentane solutions over a temperature span between θU = 19.5°C and θL = 154.5°C. The data were analyzed in terms of a relation giving η as a function of αφM, where αφ is the expansion factor for the chain dimensions in a solution with volume fraction φ of polymer with molecular weight M. It is shown that values of αφ so determined decrease as ∂ lnαφ/∂ lnφ = (1 − 2μ)/6μ for φ greater than φ* = 0.2M/s3 for moderately concentrated solutions, where s is the root‐mean‐square radius of gyration and μ = ∂ ln[η]/∂ lnM with [η] the intrinsic viscosity.