2,2'-Bis(trifluoromethyl)-4,4'-diaminodiphenyl ether (6FODA), CAS number 344-48-9, is a fluorinated diamine building block. 6FODA has an aminophenyl ether core substituted by two trifluoromethyl groups at 2,2'-positions. 2,2'-Bis(trifluoromethyl)-4,4'-diaminodiphenyl ether is usually engaged in the preparation of polyimides. These two trifluoromethyl groups hinder the π-π interaction of the benzene rings, reducing the light absorption of the polyimides. This high transparency polyimides are suitable for manufacturing flexible OLED displays. The refractive index of the polyimides can be controlled by the amount of 6FODA used in the synthesis (refractive index accuracy of ±4 × 10−4).
The casted membranes from the polyimides have good selective gas permeabilities (ideal selectivity α up to 188.43 CO2/CH4). The fabrics made from this polyimide fibers have low thermal conductivity (0.03 W/m⋅K), good flame retardancy, as well as excellent chemical and UV resistance which are ideal for aviation, military, and other special protections.