Characterization of SA-Pebax Membrane as a Potential Material for Bioethanol Dehydration

Abstract

Bioethanol, a kind of alcohol, is extensively utilized in diverse sectors including manufacturing, medications, and fuels. A bioethanol concentration above 90 wt% is necessary needed in these applications. Nevertheless, achieving this concentration is hindered by the azeotropic condition of the ethanol-water mixture. The sodium alginate (SA) membrane is a hydrophilic polymer that shows promise for use in the pervaporation of bioethanol dehydration. The performance of a SA membrane can be enhanced by blending it with other polymers. The combination of Pebax and SA can create ionic cross-links by connecting the acetate groups in SA with the amide groups of Pebax, which enhances the performance of the membrane. SA-Pebax membrane was successfully fabricated as a flat sheet with SA:Pebax blending ratio of 3:1 and 3:2. SA-Pebax membrane was fabricated using the EIPS phase separation method to form a non-porous solid membrane. The characterization results using Fourier Transform Infrared (FTIR), Scanning Electron Microscope (SEM), contact angle meter showed the effect polymer blending on the structure, morphology, and hydrophilicity properties of SA-Pebax membrane which has the potential to be applied to bioethanol dehydration by pervaporation. The surfaces blend membranes exhibited a smooth and even texture, devoid of any visible pores. Additionally, the polymer components were uniformly distributed without any phase separation. SA-Pebax membrane with 3:1 blend ratio showed the highest decrease of water contact angle value than membrane with ratio 3:2, which allowed for more efficient ethanol-water separation.