Preparation and Characterization of Thermally Rearranged Polybenzimidazole Membranes Derived from Amine-containing Polyimide for Gas Separation

Abstract

Recently, glassy polymers like PTMSP or PIM were reported to have regular microcavities in the polymer matrix. In our previous research, we reported extraordinarily permeable polymer membranes derived from ortho-functional polyimide via thermal rearrangement. Here, we would like to focus on another method to prepare polybenzimidazole(PBI) membrane with microcavities for gas separation. 6FDA and DBZ were used as monomer, and the amic solution in NMP solvent was casted on glass plate, and thermally imidized. Amino-polyimide was converted to PPy by thermal rearrangement, followed by treatment in alkaline solution. Finally, the obtained films were thermally rearranged again in a tubular furnace at 400 to 450oC. Gas permeation performance of the PBI films were characterized for various small gas molecules. Thermal stability and microscopic characteristics were investigated by several analysis instruments such as TGA, X-ray diffraction, and nitrogen adsorption/desorption experiments, etc.