On the Relationship between the Permeability Parameters of Gases and Vapors of C1-C4 Aliphatic Alcohols in Hydrophobic Polymeric Membranes

Abstract

A correlation approach for the evaluation of permeability, diffusion and solubility coefficients of lower aliphatic alcohols in polymeric membranes using basic parameters of gas transfer is proposed in this work. Previously published results of experimental study of water, ethanol and n-butanol vapors transfer in hydrophobic membranes based on glassy polymers as well as obtained new experimental data on vapor permeability of methanol, n-propanol and gases were critically reviewed. An attempt to demonstrate correlation of selective gas and vapor transfer parameters of membranes is made in the present study. The establishment of correlation of permeability of gases and C₁-C₄ aliphatic alcohols vapors in hydrophobic polymeric membranes allows to use available methods and data of gas transfer characteristics of membrane materials and membranes for estimation of the vapor separation properties, e.g., modern Data Base for gas permeability parameters of polymers can be used for evaluation of the membrane separation potential in relation to lower aliphatic alcohols. The hydrophobic polymers were selected in order to avoid specific interactions between alcohols and polymer (such as strong induction, dipole-dipole interactions and H-bond creation). Results include a preliminary estimation of diffusion coefficients of water and C₁-C₄ alcohols vapors on the basis of correlation analysis that was previously proposed for the estimation of gas transport parameters. The proposed approach allows to explain the observed characteristics of the mentioned vapors permeability in polymeric membranes and to show new relations of gases and vapors transfer in membranes. It seems that obtained results will be useful for the development of vapor-phase membrane methods of organic substances separation.