Isothermal Vapor–Liquid Equilibrium Data for the 1,1,2,2-Tetrafluoroethene + 1,1,2,2,3,3,4,4-Octafluorocyclobutane Binary System: Measurement and Modeling from (248 to 283) K

High pressure vapor–liquid equilibrium data are presented for the 1,1,2,2-tetrafluoroethene + 1,1,2,2,3,3,4,4-octafluorocyclobutane binary system. The isothermal measurements were undertaken at (248.3, 263.0, and 282.9) K, with pressures ranging from (0.040 to 2.340) MPa. A static–analytical apparatus was used to carry out the measurements. The liquid and vapor phases were sampled at equilibrium using a movable rapid on-line sampler–injector (ROLSI). The uncertainties in the measurements are less than 0.1 K, 1.5 kPa, and 0.007 for the temperature, pressure, and equilibrium phase mole fractions, respectively. The experimental data were correlated with the Peng–Robinson equation of state incorporating the Mathias–Copeman alpha function, with the Wong–Sandler mixing rule utilizing the nonrandom two-liquid (NRTL) activity coefficient model. The model accurately describes the experimental data.