STUDIES OF LINEAR POLYMER DIMENSIONS OF POLYSTYRENE IN CYCLOHEXANE OVER A WIDE-RANGE OF TEMPERATURE BY INTRINSIC-VISCOSITY

Intrinsic viscosities ([eta]) of polystyrene solutions in cyclohexane above and below the theta temperature have been measured using a capillary viscometer. The viscosity measurements were performed on five polystyrene samples with molecular weights of 6.3 x 10(4), 9.0 x 10(4), 6.0 x 10(5), 2.8 x 10(6) and 10 x 10(6). A smooth and continuous contraction was observed below the theta temperature (34.5-degrees-C). The temperature dependence of [eta] can be represented by a master curve in a alpha(eta)3\tau\M1/2 (g1/2 mol-1/2) versus \tau\M1/2 (g1/2 mol-1/2) plot, where alpha(eta) = [eta(T)]/[eta(theta)]1/3 is a viscosity expansion factor and tau = (T - theta)/T is the reduced temperature. A universal plot of reduced viscosity (alpha(eta)) versus reduced blob parameter (N/N(c)) shows the achievement of the collapsed state for the T < 0 region. The prediction of the temperature blob theory is also verified for the T > theta region.