Experimental density and PC-SAFT modeling of Krytox® (perfluoropolyether) at pressures to 275 MPa and temperatures to 533 K

Density data from 298 to 533 K and to 275 MPa are reported for Krytox® GPL 102, a poly(perfluoropropyl ether) (PFPE) with a CF3-branched fluoropropylether repeat group. The Tait equation fit to each density isotherm have mean absolute percent deviations (MAPD) between 0.11 and 0.30% with standard deviations (SD) not exceeding 0.20%. The perturbed-chain statistical associating fluid theory (PC-SAFT) fit to the density data has an MAPD of 0.67% and an SD of 0.67%. Likewise the PC-SAFT fit to previously reported density data of Demnum®, a PFPE with an n-fluoropropylether repeat group, has an MAPD of 0.22% and a SD of 0.21% for Demnum® S-20 and an MAPD of 0.27% with a SD of 0.14% for Demnum® S-65. The trends exhibited by the PC-SAFT pure component parameters obtained from the fits of these three PFPEs are similar to those reported for linear and branched hydrocarbons with the same number of carbons.

► High-temperature, high-pressure experimental density of Krytox GPL 102 is reported.
► The modified Tait equation is used to correlate the experimental density results.
► The PC-SAFT EOS is used to model the experimental density results for Krytox.
► The PC-SAFT EOS is used to model the density of Demnum, a linear analog of Krytox.
► Trends shown by PC-SAFT parameters for the polymers are similar to those of alkanes.