Patent ID: 11884787
Assignee: UNIVERSITY OF SOUTH CAROLINA
Field: Chemical engineering (Chemistry)
Classification: CPC C  B  H  Y | IPC B  C

Claim 1:
2. A process for forming the polybenzimidazole (PBI) film of claim 1 comprising:
polymerizing an aromatic or heteroaromatic tetraamino compound with at least one aromatic or heteroaromatic polycarboxylic acid or ester, anhydride, or acid chloride thereof or at least one aromatic or heteroaromatic diaminocarboxylic acid in the presence of a polyphosphoric acid solvent to form a PBI polymer solution that includes the PBI polymer in solution with the polyphosphoric acid solvent;
processing the PBI polymer solution to form a membrane precursor;
hydrolyzing at least a portion of the polyphosphoric acid to form phosphoric acid and water, thereby causing a sol-gel transfer of the PBI polymer solution and solidification of the PBI polymer to form a PBI gel membrane;
rinsing the PBI gel membrane and thereby removing the phosphoric acid from the gel membrane;
drying the rinsed PBI gel membrane as it is restrained on a porous substrate and thereby forming the PBI film.