Thermodynamic and Conformational Properties of Polystyrene. I. Light-Scattering Studies on Dilute Solutions of Linear Polystyrenes

The results of an extensive study of some dilute solution properties of a series of linear, homogeneous (anionically prepared) polystyrenes (4.8<10⁻⁴M<440) over a wide temperature interval (10°<T<110°C) in decalin and toluene are described. The data are used to obtain detailed comparisons among the second virial coefficient A₂, the mean‐square molecular radius 〈s²〉, the molecular weight M, and the temperature. The empirical correlations thus obtained are compared to theoretical predictions. In particular, it is found that A₂M^½(〈s²〉/M)${}_0^{-\frac{3}{2}}$ and α²=〈s²〉/〈s²〉₀ are each single‐valued functions of the interaction parameter z=B(〈s²〉₀/M)${}_0^{-\frac{3}{2}}$ M^½, when B is assumed to have the temperature dependence B=B₀[1—(Θ/T)]. Certain theoretical predictions for the dependence of A₂M^½/α³ on z/α³ are found to adequately describe the form of the observed behavior and can be used as the basis for a satisfactory empirical relation. The observed dependence of α² on z is satisfactorily predicted by recent calculations of Flory and Fisk. It is expected that the correlations given among A₂, α², and z will be valid for any flexible, nonionic polymer.