Synthesis and Characterization of Bifunctional Liquid-Crystalline Monomers Showing Smectic C Phase. Photopolymerization and Cross-Linking

• Published in: Chemistry of materials Vol. 8; no. 2; pp. 382 - 388
• Main Authors: Sahlén, F, Trollsås, M, Hult, A, Gedde, U. W
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14.02.1996
• Subjects: Applied sciences; Exact sciences and technology; Physicochemistry of polymers; Polymerization; Polymers and radiations; Methacrylate polymer; Bifunctional compound; Temperature effect; Smectic state; Mesomorphic state structure; Experimental study; Liquid crystals; Thermal stability; Oriented polymer; Acrylate polymer; Biphenyl derivatives; Photopolymerization; Optical properties; Preparation; Crosslinked polymer; Birefringence; Monomer
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/cm950282f

Novel syntheses of bifunctional liquid-crystalline acrylate and methacrylate monomers are described. Thermal and microstructural characterization of the monomers using small-angle X-ray scattering, differential scanning calorimetry, and optical microscopy revealed the presence of smectic A, smectic C, and smectic E phases. Photopolymerization of the bifunctional monomers conducted at different temperatures preserved the monomeric liquid-crystalline structure in the cross-linked polymers. The densely cross-linked polymers showed thermal reversibility. Mixtures of these monomers and chiral monofunctional liquid-crystalline monomers exhibited chiral smectic C mesomorphism that was permanented by photopolymerization and subsequent cross-linking.