Defect Free Nonporous Polyurethane Membrane; Preparation, Characterization And Performance In Gas Separation

Abstract

This article aims to fabrication of Polycaprolactone based Polyurethane as a gas barrier membranes. To enhance the membrane performance, diisocyanates and chain extender were incorporated into a polyurethane matrix. Different synthesis conditions were investigated and the membrane morphologies were characterized by FTIR, TGA, DSC, and AFM. The Permeation properties of the prepared membranes were studied as a function of processing methodology. The results show that polymers with high molecular weight and sonication instead of electrical stirring gave significantly better barrier properties. The permeance of gases increase with increase of temperature resulting in the reduction of COR2R/CHR4R selectivity in 1,6-Hexamethylene diisocyanate (HDI) based Polyurethane membranes. But, the COR2R/NR2R selectivity in4,4’- methylene dicyclohexyl diisocyanate (HR12RMDI) PUs is little bit higher. Because the permeation of more condensable COR2R gas in comparison to nonpermeable nitrogen increase in more phase separated structures, therefore effect of the solution selectivity in the separation of condensable and non-condensable gases increase and this membrane show the higher COR2R/NR2R selectivity in comparison to the HDI system.