Designed poly(ether-imide)s and fluoro-copoly(ether-imide)s: Synthesis, characterization and their film properties

摘要

Two series of amorphous fluoro-poly(ether-imide) (6F-PEI) and one series of fluoro-coploy(ether-imide) (6F-CoPEI) polymers based on 2,2′-bis(3,4-dicarboxyphenyl) hexafluropropanedianhydride (6FDA) and di-ether-containing diamines: 1,2′-bis(4-aminophenoxy)benzene (o-BAPOB) and 4,4′-bis(4-aminophenoxy)diphenyl sulfone (p-SED) were synthesized. The solution properties, chemical resistance, thermal stability, mechanical properties, thermo-oxidative and hydrolytic stability of selected 6F-PEIs and 6F-CoPEIs were studied. The dielectric constant (ε′) values of 6F-PEI and 6F-CoPEI were estimated by additive group contribution calculation using mathematical equations defined by the Lorentz-Lorenz's theory and the Vogel's theory, and by Vora-Wang equations, respectively. These polymers not only showed excellent electrical properties but also excellent long-term thermo-oxidative stability and reduced water absorption relative to non-fluorinated polyimides. The estimated dielectric constant of these polymers (ε′ < 3.15) were lower than those of commercially available poly(ether-imide) ULTEM~® 1000 and polyimides Kapton~®H, respectively at 1 kHz. The analytical results are summarized and discussed.