Intrinsic viscosity and axial extension ratio of random-coiling macromolecules in a hydrodynamic shear field

The shear dependence of the intrinsic viscosity and the conformation of high molecular weight polyisobutylene in dilute solutions of decahydronaphthalene under shear were determined simultaneously. Experimental variables investigated were the shear rate (0 to 2 × 10³ sec^?1), the molecular weight (1.0 × 10⁷ to 1.7 × 10⁷) and the polymer concentration (1.8 × 10^?4 to 8.4 × 10^?4 g/cc). Correlations allowing concentration and shear rate normalization for any one sample are described. Conformational extention ratios along the orientation direction of the deformed molecule to 1.42 and intrinsic viscosity ratios (sheared to zero shear) to 0.5 were observed.