Low pressure CO2 sorption in poly(vinyl cyclohexane-carboxylate)

A gravimetric method was applied to determine the solubility of CO₂ in poly(vinyl cyclohexanecarboxylate) below 1 atm. The temperatures were varied from 5 to 85°C, above and below the glass transition temperature. The sorption isotherms were concave to the pressure axis below T_g and they were tentatively analyzed by the dual-mode sorption model. Above T_g, the isotherms were linear and described by the Henry's law. Below 75°C, the diffusion coefficients of CO₂ were also obtained from the half-time of the sorption process.