The hybrid membrane/distillation process has been suggested as an alternative to the conventional energy-intensive olefin/paraffin separation technology. In this study, bulky ethyl substituent-containing polyimides were synthesized from various aromatic dianhydrides and 4,4'-methylenebis (2,6-diethylaniline) by azeotropic imidization, and its gas tranport properties were investigated. Ethyl groups were placed ortho to the imide nitrogen, which hinders backbone rotation, chain packing, and flexibility. The synthesized polyimides exhibited a good thermal stability with high glass transition temperatures (268-285 ℃). The prepared polyimide membranes exhibited high propylene/propane selectivity and lied near to the upper bound line.

• 유승연(한양대학교 에너지공학과) | Seung Yeon Yoo
• 박호범(한양대학교 에너지공학과) | Ho Bum Park