Side-chain liquid-crystalline poly(ketone)s: effect of spacer length, mesogen type and mesogen density on mesomorphic behavior

• Published in: Macromolecular chemistry and physics 2000-11, Vol.201 (17), p.2484-2492
• Main Authors: Nieuwhof, René P., Marcelis, Antonius T. M., Sudhölter, Ernst J. R., Wursche, Roland, Rieger, Bernhard
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Laboratorium voor Organische chemie; Laboratory for Organic Chemistry; Organic Chemistry; Organic polymers; Organische Chemie; Physicochemistry of polymers; Polymers with particular structures; Preparation, kinetics, thermodynamics, mechanism and catalysts
• ISSN: 1022-1352; 1521-3935
• DOI: 10.1002/1521-3935(20001101)201:17<2484::AID-MACP2484>3.0.CO;2-X

Novel side‐chain liquid‐crystalline copolymers (SCLCPs) were synthesized via the Pd(II) catalyzed alternating copolymerization of mesogenic 1‐alkenes and carbon monoxide. For methoxybiphenyl mesogens, these copolymers exhibited highly ordered smectic E mesophases and high glass transition temperatures. The transition temperatures of these polymers were tuned by altering the spacer length or by dilution of mesogen‐containing alkenes with 1‐hexene. Polymers with cyanobiphenyl or methoxyazobenzene mesogens exhibited nematic mesophases. These polymers were the first ever nitrogen containing copolymers of this type. Increase of the spacer length or the 1‐hexene content of methoxybiphenyl‐containing copolymers resulted in a decrease of the surface polarity of spincoated films. The decomposition temperature of these SCLCPs started far above the isotropization temperature of the polymers.