Interactions of organic halides with a polyurethane elastomer

Interactions of halogen-substituted organic penetrants have been studied with a polyurethane membrane over the temperature interval of 25-60°C. Transport parameters such as diffusivity, solubility, and permeability have been measured. A temperature dependence of these quantities has been used to predict activation parameters for the transport mechanism. Equilibrium sorption data were used to estimate the entropy and Gibbs energy for the sorption process by using the Van't Hoff relationship. Furthermore, a phenomenological treatment has been suggested to estimate the classical Flory-Huggins interaction parameter for polyurethane-solvent pairs. These data were used to calculate the molar mass between crosslinks of the polyurethane network. For all the penetrants, the transport mechanism was found to be anomalous.