Transport of mixed solvents in glassy polymer membrane

Transport of mixed solvents in polymer membrane was investigated using quartz spring weighing method. Absorption kinetic curves for two mixed solvent systems, ethanol/1,2-dichloroethane and ethanol/ethyl acetate, in polyurethane (PU) were measured. Solubility of solvent in PU membrane was studied using a model that incorporates Henry law and BET adsorption theory. Taking into account the interactions between different solvents, a dual-mode transport model for mixed solvents in glassy polymer membrane was developed to fit the experimental data. The correlation is satisfactory. The same set of parameters can be used to fit the data over a wide range of concentrations indicating the prediction potential of the model.