Preparation and thermal properties of semi-rigid rod-like homo- and copoly(ester-imide)s containing diphenyl ether dicarboximide units

✍ Scribed by Moriyuki Sato; Tomohiro Hirata; Seiji Ujiie

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 658 KB
• Volume: 30
• Category: Article
• ISSN: 1381-5148
• DOI: 10.1016/1381-5148(96)00025-9

✦ Synopsis

Novel semi-rigid rod-like homo-and copoly(ester-imide)s, composed of 3,4,3',4'-diphenyl ether dicarboximide rings having no N-phenyl groups next to the imide ring, were synthesized by transesterification of a dihexanol derivative of 3,4,3',4'-diphenyl ether dicarboximide and/or a dioxydihexanol of biphenyl with aliphatic dimethyl esters. The thermal and mesogenic properties of these polymers were evaluated. The expected structures of the polymers were confirmed by FTIR, 13C-NMR spectroscopy and elemental analyses. From DSC measurements. optical texture observations by means of a polarizing microscope equipped with a hot stage, and temperature-dependent X-ray analyses, it was determined that the biphenyl-unit-rich polymers form nematic phases, but the diphenyl ether dicarboximide containing homopolymers have no liquid crystalline phases in the melt. It was suggested that the mesogenic character of the 3,4,3',4'-diphenyl ether dicarboximide ring is low. TG-DTA measurements showed that the polymers are thermally stable up to 300°C in air.