SYNTHESIS AND CHARACTERIZATION OF BIFUNCTIONAL LIQUID-CRYSTALLINE MONOMERS SHOWING SMECTIC-C PHASE - PHOTOPOLYMERIZATION AND CROSS-LINKING

Novel syntheses of bifunctional liquid-crystalline acrylate and methac rylate monomers are described. Thermal and microstructural characteriz ation 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 th e bifunctional monomers conducted at different temperatures preserved the monomeric liquid-crystalline structure in the cross-linked polymer s. The densely cross-linked polymers showed thermal reversibility. Mix tures of these monomers and chiral monofunctional liquid-crystalline m onomers exhibited chiral smectic C mesomorphism that was permanented b y photopolymerization and subsequent cross-linking.