Syntheses and properties of aromatic polyimides based on 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane and 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenylethane

A series of fluorinated polyimides were prepared from 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane with various aromatic tetracarboxylic dianhydrides via a conventional two-step procedure. These polyimides were amorphous in nature and afforded flexible and tough films. Some polyimides derived from less stiff dianhydrides were soluble in polar organic solvents. The glass-transition temperatures (T-g) of these polyimides ranged from 252 to 324degreesC, and softening temperatures (T-s) stayed in the 254similar to322degreesC range. Decomposition temperatures (T-d) at 10% weight loss all occurred above 569 C in both air and nitrogen atmospheres. For a comparative study, another series of analogous polyimides based on 1,1-bis[4-(4-aminophenoxy)phenyl]-1-phenylethane were also pepared and characterized.