The permeability coefficients of five different 2

2 - bis (3

4 -dicarboxyphenyl) hexafluoropropane dianhydride (6FDA)-based polyimide membranes to H2

CO2

O2

N2 and CH4 have been measured at 0. 6MPa and at the temperatures from ambient up to 100 ℃. The temperature and pressure dependency of permeability coefficients of 6FDA-based polyimides is smaller than other standard glassy polymers having more flexible backones. 6FDA-DABP and 6FDA-DMMDA have still higher permeability coefficients at 100℃. The favorable gas separation property

excellent thrmal and mechanical durability

and good processability make 6FDA-DABP and 6FDA-DMMDA to be promis-ing candidate for membrane-based gas separation application.