PERVAPORATION OF WATER ACETIC-ACID THROUGH POLYIMIDE MEMBRANES FROM 3,3',4,4'-BENZOPHENONE TETRACARBOXYLIC DIANHYDRIDE AND 4,4'-OXYDIANILINE

Pervaporation performance of polyimide (PI) membrane from 3,3',4,4'-benzophenone tetracuboxylic dianhydride (BTDA) and 4,4'-oxydianiline (ODA) was investigated at 80wt% feed acetic acid concentration and at 65-degrees-C. Imide contents in PI film were estimated by thermogravimetric analysis (TGA) method. The separation factor of PI membrane increases with the degree of imidization, while the flux was almost constant. The separation factor toward water through PI-94 membrane was about 417 with the flux of 47 g/m2.hr measured at 65-degrees-C and with 80wt% acetic acid as a feed. PI-94 showed the best pervaporation performance toward the separation of water from acetic acid solution among the PI membranes investigated. The swelling behaviors at various feed concenration were also examined.