Aromatic Poly(ether imide)s Bearing Isopropylidene or Hexafluoroisopropylidene Links in the Main Chain

Abstract

Two bis(ether anhydride) monomers, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride (4) and 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]hexafluoropropane dianhydride (4-F), were synthesized from readily available compounds in three steps in high yields. Two series of poly(ether imide)s 7a-g and 7a-g-F based on dianhydrides 4 and 4-F, respectively, were synthesized by a conventional two-step procedure that included a ring-opening polyaddition to give poly(amic acid)s, followed by cyclodehydration to polyimides. The intermediate poly(ether amic acid)s and the poly(ether imide)s had inherent viscosities in the range of 0.29–1.09 dL g−1 and 0.21–0.98 dL g−1, respectively. Except for the poly(ether imide)s derived from benzidine, the others afforded flexible and tough films. Most of the obtained poly(ether imide)s are organic-soluble. The glass transition temperatures (Tg) of these polymers ranged from 204 to 259°C. Degradation temperatures for 10% weight loss all occurred above 505°C in nitrogen and above 501°C in air. Fluorine-containing poly(ether imide)s showed higher solubility, Tgs and degradation temperatures in nitrogen, as compared to their respective nonfluorine-containing counterparts.