Determination of the Viscosity-Shear Behavior of Polymer Containing Fluids Using a Single Pass, High-Shear Capillary Viscometer

A Penn State, single-pass, capillary high shear viscometer redesigned for use at shear rates up to 10⁶ s⁻¹ and viscosity levels as low as 2 cp. is described. The capability of handling the effects of temperature, pressure and kinetic energy changes of Newtonian fluids over a wide range of shear rates and viscosities has been demonstrated by using a series of capillaries of different lengths and diameters. The non-Newtonian characteristics of polymer containing fluids can be obtained with good precision by using the calibrated high-shear viscometer to determine the difference in flow behavior between a Newtonian and a non-Newtonian oil with similar temperature, pressure and kinetic energy corrections.

This modified viscometer has been demonstrated with a series of viscosity index improved oils using VI improvers typical of current automotive crankcase lubricants. The viscosity shear behavior of these polymer blends was determined over the range of 10² to 10⁶ s^-1 shear rates at 121°C (250°F) and 149°C (300°F).