Second Virial Coefficients for Solutions of Polystyrene Mixtures Obtained With Low-Angle Laser Light Scattering

Low-angle laser light scattering measurements were performed on practically binary mixtures of standard polystyrenes dissolved in toluene. Second virial coefficients A₂ were obtained as a function of the composition of the mixed polymer. No solid evidence was found for the existence of maxima in A₂ vs composition. Existing theories predict a maximum. The possible existence of minima such as reported by Suzuki⁵ could not be confirmed with the present system.