The phase behavior of the ternary system Nylon 6/2,2,2-trifluoroethanol/CO2 has been examined at 298.15, 318.15, and 373.15 K and pressures up to 40 MPa. The ternary system exhibits solid-liquid-vapor equilibrium at 298.15 and 318.15 K and liquid-liquid-fluid equilibrium at 373.15 K. At 298.15 and 318.15 K and 10.34 MPa, a metastable equilibrium exists and the time for phase separation depends on the Nylon 6 composition and temperature. CO2 behaves as a useful diluent for the Nylon 6/TFEtOH mixture at Nylon 6 concentrations below 4 wt %,as large amounts of CO2 can be added while maintaining a reasonable Nylon 6 solubility. At 373.15 K, the ternary system exhibits liquid-liquid instability and CO2 behaves as an excellent diluent in two regions : (1) region with a high Nylon 6 concentration, where a small amount of CO2 can enhance the Nylon 6 solubility in TFEtOH; (2) region with a low Nylon 6 concentration, similar to the results obtained at 298.15 and 318.15 K. The acquired experimental data are correlated using two state-of-the-art theoretical models : (1) SAFT and (2) Sanchez-Lacombe-Perram equation of state.