Ternary fluoro-containing polyimide blends and fluoro-containing polyimide/poly ester blends

Two ternary miscible fluoro-polyimide blends have been identified. They are 6FDA-3,3′-6F-diamine/6FDA-4,4′-6F-diamine/BTDA-4,4′- 6FDAblendand6FDA-3,3′-6F-diamine/6FDA - 4,4′ - 6F - diamine/ODPA - PMDA - 4,4′-6F-diamine blend (6FDA is 2,2′-bis(3,4′-dicarboxyphenyl)hexafluoro propane dianhydride, 6F-diamine is 2,2′-bis(3-aminophenyl) hexafluoro propane). Their miscibility probably arises from the fact that their diamine parts have hexafluoro isopropylidene groups, their dianhydride parts have similar bond angle, space, rigidity and length. Several 6FDA-polyimides and PCTG 5445 (glycol-modified polycyclohexanedimethanolterephthalate) forming miscible blends have also been discovered. These surprising results suggest that hexafluoro-isopropylidene-group containing polyimides are quite intermodular active and the 1,4-cyclohexane dimethanol component in PCTG 5445 may also offer unique miscibility capability.