Viscosity and Density of an ISO VG 32 Polyol Ester Lubricant Saturated with Compressed Hydrofluorocarbon Gases: R-134a, R-32, and R-125
Ana Rita C. Morais, Luke D. Simoni, Mark B. Shiflett, Aaron M. Scurto
Abstract
The dynamic viscosity and density measurements for mixtures of synthetic polyol ester (POE) lubricating oil (ISO VG 32) saturated with compressed 1,1,1,2-tetrafluoroethane (R-134a), pentafluoroethane (R-125), and difluoromethane (R-32) were conducted over a wide temperature range (248.15 K, 273.15 K, 323.15 K, and 348.15 K) and pressures up to 1.0 MPa. The viscosity and density data ranged from 2845 to 6 mPa·s and 1019 to 948 kg·m–3, respectively. Previously reported vapor–liquid equilibrium and modeling data were used to predict the liquid composition for both viscosity and density as a function of temperature and pressure. Redlich–Kister expansions were used to correlate the measured viscosity and density for each HFC/lubricating oil system. Experimental and modeling data were used to calculate the kinematic viscosities and generate Daniel plots.