Rheological Properties of Narrow Distribution Polystyrene Solutions

Experimental non-Newtonian viscosity, primary normal stress difference, dynamic viscosity, and dynamic storage modulus data were obtained for 16 viscoelastic fluids. The fluids investigated were solutions of almost monodisperse polystyrene in Aroclor (a mixture of chlorinated diphenyls). Several nonlinear rheological equations of state were fit to the experimental data, and the Bird-Carreau model was found to fit the data within 15% for every solution investigated. Bird-Carreau model parameters were determined by use of a nonlinear least-squares computer analysis, and these parameters were related to polymer molecular weight and concentration. Experimental values of the steady-state compliance were obtained from primary normal stress difference and shear stress data. These values agreed with the Rouse theory prediction.