Highly optically transparent/low color polyimide films prepared from hydroquinone- or resorcinol-based bis(ether anhydride) and trifluoromethyl-containing bis(ether amine)s

摘要: Abstract Two series of novel polyimides (5a–g and 6a–g) containing flexible ether linkages pendent trifluoromethyl (CF3) groups were synthesized from 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride (3a) 1,3-bis(3,4-dicarboxyphenoxy)benzene (3b) with various CF3-substituted aromatic bis(ether amine)s (4a–g) via ring-opening polyaddition to poly(amic acid)s, followed by thermal or chemical imidization. These readily soluble in a variety organic solvents could be solution-cast into tough films. The cast films exhibited high optical transparency almost no color, UV–vis absorption edge 368–382 nm very low b∗ value (a yellowness index) 6.2–15.5. They had good stability glass-transition temperatures 186–288 °C, most them did not show significant decomposition before 500 °C. Moreover, these polyimide also possessed dielectric constants 2.79–3.49 (at 1 MHz) water uptakes (