Polyetherimides are versatile melt-processable engineering resins. A series of fluoro-polyetherimides compositions based on diether-containing diamines were designed on paper and their dielectric constants (epsilon') estimated before their synthesis. Experimentally determined epsilon' values were compared with the estimated values. The amorphous polyetherimides containing bis-trifluoromethyl groups exhibited not only low dielectric constants-lower than those of the commercially available polyetherimide ULTEM 1000 and polyimide Kapton H at 1 kHz- but also excellent long-term thermo-oxidative stability and reduced water absorption relative to non-fluorinated polyimides.