Polymer diffusion and dimensions in moderately concentrated solutions

Abstract

The diffusion of linear atactic polystyrenes (M_w= 110 000 and 200 000) in cyclohexane has been determined at and above the theta temperature over the temperature range 35–60 °C using Rayleigh linewidth spectroscopy for moderately concentrated solutions (0.1–1%). From these data hydrodynamic radii have been calculated and related to the radius of gyration determined by intensity light scattering. Comparison is made with the Kirkwood–Riseman bead-and-spring model for the polymer and approximate agreement is obtained.