Thermotropic liquid-crystalline aromatic-aliphatic polyimides, 3. Poly(imide-carbonate)s composed of 3,4:3′,4′-biphenyldicarboximide

✍ Scribed by Tomohiro Hirata; Moriyuki Sato; Ken-ichi Mukaida

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 649 KB
• Volume: 195
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1994.021950513

✦ Synopsis

Abstract

N,N′‐Bis(ω‐hydroxyalkyl)‐3,4:3′,4′‐biphenyldicarboximide (l = 3, 6) were prepared by a two‐step reaction (via intermediates) of 3,4:3′,4′‐biphenyltetracarboxylic dianhydride and ω‐amino‐alcohols. Polycondensation of dihydroxyalkyl derivatives of the 3,4:3′,4′‐biphenyldicarboximide (l = 3, 6) and/or biphenyl with alkylene bis(phenylcarbonate)s (m = 3, 6) afforded poly(imidecarbonate)s with high molecular weights in high yields, which were characterized by FT‐IR and NMR measurements and elemental analyses and showed good solubilities in organic solvents. The mesogenic properties of the polymers were evaluated by means of differential scanning calorimetry (DSC), observation in the polarizing microscope equipped with a hot stage and by means of powder X‐ray diffraction. The DSC curves of the imide unit rich polymers without annealing only display glass transition steps. The curves after annealing, however, show some endotherms. The polarizing microscope observation and X‐ray analyses indicated that the homo‐and copolymers from the 3,4:3′,4′‐biphenyldicarboximide derivative with longer methylene chains (l = 6) form nematic liquid‐crystalline mesophases.