Applying lattice-hole theory to gas solubility in polymers

Abstract.

A recent theory based on the Simha-Somcynsky theory is applied to the solubility of the 1,1,1,2-tetrafluoroethane vapor in polystyrene. The requisite chemical potentials of the vapor and of its condensate in contact with the polymer involve the equations of state (eos) of the 3 species and are evaluated by means of literature information. Good agreement with experiment ensues at 120 °C and pressures up to 35 bar. At 90 °C systematic differences, increasing with pressure, result above 10 bar. These may be caused by the use of melt theory in the glass transition region and/or an inadequacy of the eos of the vapor at lower temperatures and elevated pressures. Extensions to further pairs, gaseous mixtures and the glassy state are indicated.