A gas separating asymmetric membrane such as a gas separating asymmetric hollow fiber comprises an aromatic polyimide of which recurring unit is expressed by the formula (I):
wherein A¹ is a tetravalent unit at least 40 molar % of which has a diphenylhexafluoropropane structure, and A² is a divalent unit at least 35 molar % of which is a divalent unit derived from a diaminobenzothiophene or a diaminodiphenylenesulfone.
气体分离非对称膜(如气体分离非对称中空纤维)由芳香族聚
酰亚胺组成,其递归单元由式(I)表示:
其中 A¹ 是四价单元,其中至少 40 摩尔%的单元具有二苯基
六氟丙烷结构,A² 是二价单元,其中至少 35 摩尔%的单元是衍生自二
氨基
苯并噻吩或二
氨基二苯基砜的二价单元。