Abstract
Abstract Intrinsic viscosities of poly(4‐chlorostyrene) solutions in isopropyl‐benzene and n ‐propylbenzene at temperatures above and below the theta (θ) temperatures of these solvents were measured using a capillary viscometer. The viscosity measurements were performed on three poly(4‐chlorostyrene) samples having molecular weights (M̄; v ) 1.75 × 10 6 , 6.5 × 10 5 and 2.7 × 10 5 . A smooth and continuous contraction below the θ temperatures was observed for both solvents. The temperature dependence of [/eta] can be represented by a master curve in a plot of α 3 /eta|/tau| M 1/2 (g 1/2 mol −1/2 ) versus |/tau| M 1/2 (g 1/2 mol −1/2 ), where α/eta = [/eta( T )]/[/eta(θ)] 1/3 is the expansion factor and /tau = ( T ‐ θ)/ T is the reduced temperature. A universal plot of reduced viscosity size (α/eta) versus reduced blob parameter ( N/N c ) shows the achievement of collapsed state for T <θ. The prediction of thermal blob theory is also verified for T > θ. The temperature dependence of intrinsic viscosity, both below and above the θ temperature, exhibits similar behaviour to the temperature dependence of dipole moments for both of these solvents.