Organosoluble, low-colored fluorinated polyimides based on 1,1-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]-1-phenyl-2, 2,2-trifluoroethane

A novel trifluoromethyl-substituted bis(ether amine) monomer, 1,1-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane, was synthesized that led to a series of novel fluorinated polyimides via chemical imidization route when reacted with various commercially available aromatic tetracarboxylic dianhydrides. These polyimides were highly soluble in a variety of organic solvents such as N-methyl-2-pyrrolidone and N,N-dimethylacetamide, and most of them could afford transparent, low-colored, and tough films. These polyimides exhibited glass-transition temperatures (T(g)s) of 227-269 degrees C and showed no significant decomposition below 500 degrees C under either nitrogen or air atmosphere. These polyimides had low dielectric constants of 2.87-3.17 at 10 kHz, low water uptake of 0.13%-0.58%, and an ultraviolet-visible absorption cutoff wavelength at 364-410 nm. For a comparative study, a series of analogous polyimides based on 1, 1-bis[4-(4-aminophenoxy)phenyl]-1-phenyl-2,2,2-trifluoroethane were also prepared and characterized.