A Z type sexiphenyltetracarboxylic dianhydride, 3,3′′′′′,4,4′′′′′-1,1′:2′,1′′:4′′,1′′′:4′′′,1′′′′:2′′′′,1′′′′′-sexiphenyltetracarboxylic dianhydride (1), was synthesized in seven steps from diethyl 4-bromophthalate. Aromatic polyimides (PI1x) were synthesized from 1 and various aromatic diamines (x) by both a conventional two-step procedure and a one-step procedure, and the properties were compared with those of the polyimides (PI2x) previously prepared from rigid 3,3′′′′′, 4,4′′′′′-p-sexiphenyltetracarboxylic dianhydride (2), the isomer of 1. The values of glass transition (Tg) temperatures are much higher (270–345 °C) than those of the corresponding PI2x, and the decrease in the storage modulus at Tg is larger than that of the corresponding PI2x.
- Takafumi Nakagawa
- Atsushi Morikawa