Dew and bubble point pressures for bifunctional hydroxyl-terminated perfluoropolyether oligomers and supercritical carbon dioxide (SCCO2) were measured in the range (50-80)degrees C. The oligomers used in the measurements were purified for the present work in order to obtain four fractions with molar mass (M-n) in the range (598-4391)g/mol and dispersity close to one. The maximum pressures for the existence of phase split increase from approximately (12-13) MPa at 50 degrees C to (17-20) MPa at 80 degrees C, with increasing values, at given temperature, with Mn. Over the investigated ranges, the solubility of the oligomers in SCCO2 varies substantially (from 23 g/kg to 318 g/kg), increasing with pressure and decreasing with temperature. For M-n >= 1140, the solubility monotonically decreases with M-n. In this range, the experimental data indicate that SCCO2 is a viable solvent for the fractionation of these oligomers on the basis of M-n. (C) 2015 Elsevier B.V. All rights reserved.