Colorless and Organosoluble Fluorinated Poly(ether imide)s Containing A Asymmetry, Bulky Featured 4-tert-Butylcatechol Bis(ether anhydride) and Trifluoromethyl Substituents Aromatic Bis(ether amine)s

A series of fluorinated poly (ether imide)s (PEIs) were prepared from asymmetry, bulky featured of 1,2-bis(3,4-dicarboxyphenoxy)-4-tert-butylbenzene dianhydride and various trifluoromethyl-based bis(ether amine)s via conventional thermal (H) or chemical (C) imidization. All fluorinated PEIs exhibited flexible, good mechanical properties and excellent solubility in a variety of organic solvents. In addition, the chemical imidization based PEI thin films showed cut-off wavelengths of UV-vis absorptions below 380 nm with very low yellowness index (b* < 5.5). They also exhibited high thermal stability with the 10 % weight loss temperature from 486 to 550 °C of in nitrogen or air atmosphere. Compared with the corresponding PEIs based on non-fluorinated bis(ether amine)s, fluorinated PEIs not only showed higher optical transparency, lower dielectric constants and water absorptions but also maintained thermal and mechanical properties.