Sorption of propane in poly(ethyl methacrylate) near Tg

The sorption of propane in poly(ethyl methacrylate) was investigated above and below the polymer T_g and the dual-mode sorption model parameters were evaluated. The Langmuir capacity decreased as the temperature was raised to T_g and the apparent Henry's law constant exhibited a discontinuity at T_g. The enthalpy of microvoid filling ΔH_H is more exothermic than the enthalpy of dissolution at T < T_g by about 8 kJ/mol.