An analysis of excluded‐volume effects in a polystyrene‐cyclohexane system

Abstract

AbstractAn attempt was made to analyse Miyaki's data for the radius of gyration <s2> and the intrinsic viscosity [η] of very high molecular weight samples of polystyrene in cyclohexane. The excluded‐volume variable z was estimated by adopting the temperature dependence of the excluded‐volume integral as predicted by Eichinger. It was found that the volume expansion as given by the ratio of <s2> to <s2>0 under the unperturned state was a function of z only, as required by two‐parameter theories. These data were in good agreement with the Domb‐Barrett and the Suzuki equations. On the other hand, the ratio of [η] to [η] 0 under the unperturbed state also gave a single composite curve when plotted against z. However, it was found that the observed hydrodynamic behaviour was not satisfactorily explained by two‐parameter theories of [η]. A brief comment was made on the validity of two‐parameter theories from the experimental point of view.