Prediction of High Temperature Viscosities of Polymer Solutions up to 10 ⁷ sec ^-1 Shear Rates

The Penn State high shear viscometer has been used to measure viscosities of polymer solutions at shear rates up to 10⁶ sec^-1 over a temperature range of 20°C to 175°C. A double truncated power law model has been developed for analysis of the primary data from the viscometer. This model can be used to determine the shear rate at which incipient non-Newtonian behavior occurs, the power law index, and the shear rate at which a second Newtonian region is found. These three parameters appear to be regular functions of temperature for a given polymer (Viscosity Index Improver) type. The correlation of these three functions with temperature provides a convenient method of predicting viscosity properties of polymer solutions at various temperatures and shear rates up to 10⁷ sec^-1.

The Penn State high shear viscometer has been used to evaluate methacrylate and olefin copolymer VI improvers in mineral oil base stocks at shear rates of 10⁶ sec^-1 at various temperatures. These data are then used to provide viscosity values at shear rates of 10⁷ sec^-1.