More on the Analysis of Dilute Solution Data: Polystyrenes Prepared Anionically in Tetrahydrofuran

Further comments on the analysis of dilute solution data are provided. Light-scattering and intrinsic-viscosity data used for this purpose are those obtained for monodisperse polystyrenes, prepared anionically in tetrahydrofuran, in benzene, toluene, and dichloroethane at 30°C and in cyclohexane at temperatures ranging from 32.2 to 60.1°C. The value of [η]θ/M1/2 is somewhat greater than the corresponding value for Berry’s polystyrenes prepared anionically in benzene, where [η]θ is the intrinsic viscosity at the theta temperature and M is the polymer molecular weight. This suggests that the two types of samples differ in microstructure, though the precise difference is unknown. However, it is shown that the two-parameter relationships established experimentally in the previous papers are well reproduced in the present data. The relationships are different from those determined by Kato, et al., for monodisperse poly(α-methylstyrene) prepared anionically. Since there is shown to be no essential difference between our and their methods of determining mean-square radii, it seems unlikely that the difference is related to measurements and subsequent treatments. It is suggested rather that the problem is related to Kato’s samples.