Henry's law coefficients for monomers and selected solvents in amorphous tetrafluoroethylene-hexafluoropropylene copolymers

paper presents Henry's law coefficients for tetrafluoroethylene (TFE) and hexafluoropropylene (HFP) monomers, their dimers, and a number of potential process solvents in amorphous TFE-HFP copolymers. A standard inverse gas chromatographic method was used for the measurements. Results are presented to validate the experimental techniques and data reduction methods by comparison with published literature values for polystyrene with selected solvents. The specific amorphous TFE-HFP copolymer used for these measurements was characterized by fluorine NMR as consisting of 53 mol % HFP and 47 mol % TFE with 15% of the HIPP as diads. A number-average molecular weight of 104 000 with a polydispersity of 2.81 was determined by gel permeation chromatography analysis. A total of 19 binary systems were measured for this polymer at 4-6 temperatures over the range of (321 to 511) K. The experimental data are correlated by fitting with an Arrhenius temperature dependency.