Two series of fluorinated polyimides were prepared from 2,2'-bis(4-amino-2-trifluoromethylphenoxy)biphenyI (2) and 2,2'-bis(4-amino-2-trifluoromethylphenoxy)-1,1'-binaphthyl (4) with various aromatic dianhydrides via a conventional, two-step procedure that included a ring-opening polyaddition to give poly(amic acid)s, followed by chemical or thermal cyclodehydration. The inherent viscosities of the polyimides ranged from 0.54 to 0.73 and 0.19 to 0.36 dL/g, respectively. All the fluorinated polyimides were soluble in many polar organic solvents, such as N,N-dimethylacetamide and N-methylpyrrolidone, and afforded transparent and light-colored films via solution-casting. These polyimides showed glass-transition temperatures in the ranges of 222-280 and 257-351 degreesC by DSC, softening temperatures in the range of 264-301 degreesC by thermomechanical analysis, and a decomposition temperature for 10% weight loss above 520 degreesC both in nitrogen and air atmospheres. The polyimides had low moisture absorptions of 0.23-0.58%, low dielectric constants of 2.84-3.61 at 10 kHz, and an ultraviolet-visible absorption cutoff wavelength at 351-434 nm. Copolyimides derived from the same dianhydrides with an equilmolar mixture of 4,4'-oxydianiline and diamine 2 or 4 were also prepared and characterized. (C) 2004 Wiley Periodicals, Inc.