Rheological characterization of polyisobutylene solutions from rod-climbing experimentation

Rod-climbing constants and first-normal stress differences of polyisobutylene (PIE) solutions are obtained from rod-climbing experiments. For a low deformation rate, the polymer solution can be regarded as a second-order fluid, and the rod-climbing constant for second-order fluids is correlated with the rheological properties of the polymer solutions. The rod-climbing constants for solutions of PIB in polybutene decrease with temperature, and increase with rod size, polymer concentration, molecular weight of the polymer, and solvent viscosity. The rheological properties were measured using RMS-800, and compared with those obtained from rod-climbing experimentation.