Structure of mixed matrix membranes made with SAPO-5 zeolite in polyurethane matrix

SAPO-5 zeolite has been used to modify the structure of polyurethane membranes and to improve their properties. Scanning electron microscopy (SEM), Fourier Transform Infrared spectroscopy (FTIR), Bubble-point test, water permeability, swelling in water and several alcohols (methanol, ethanol, 1-propanol and 1-butanol) and density measurements have been used to study the incorporation of SAPO-5 zeolite in polyurethane membranes, the changes of supramolecular structure of polyurethane in the membrane network and the structural uniformity of the obtained membranes. As a function of the preparation method, anisotropic membranes can be obtained. The incorporation of SAPO-5 zeolite in polyurethane matrix also induces changes in the membrane morphology. The zeolite plays a cross-linking function in the membrane structure. All the tested membranes show a tendency to swell with ethanol.