Measurement and Correlation of Densities and Dynamic Viscosities of Perfluoropolyether Oils

The densities and dynamic viscosities of five different polydisperse perfluoropolyethers (PFPE) were measured at atmospheric pressure over the combined temperature range 263.15-373.15 K. For one PFPE being considered as a high-temperature high-pressure viscosity standard reference material, measurements were made on two separate samples to examine the lot-to-lot variability in density and viscosity; significant variability was observed only for the viscosity data. Experimental data were correlated as a function of temperature. A simple quadratic equation was used for density, while three equations (DIPPR, VET, and Waterman) were applied to the viscosity data. The DIPPR equation represented the viscosity data with deviations approximately an order of magnitude lower than the other two equations.