Synthesis and Solid-State Polymerization of Liquid-Crystalline Acrylic Monomers Containing Chiral Epoxy Groups

Tadafumi Shindo, Toshiyuki Uryu

Solid-state polymerization of liquid-crystalline monomers by low energy electron beam was examined. Six kinds of mono-functional acryloyl monomers having phenyl benzoate as mesogen were synthesized. Of them, two monomers had a chiral epoxy group as well. All polymers and monomers were studied by differential scanning calorimetry, cross-polarizing microscopy and NMR. The presence of the epoxy group stabilized liquid-crystalline phase. In spite of mono-functional acryloyl monomers, monomers containing an epoxy group gave insoluble crosslinked polymers by EB irradiation, while radical polymerization provided a soluble polymer. The solid-state CP/MAS 13C NMR spectrum of the crosslinked polymer was similar to that of a radically-polymerized, linear polymer. DSC and crosspolarizing microscopy measurements exhibited that the crosslinked polymer had phase transition due to crystal-to-smectic, smectic-to-nematic and nematic-to-isotropic changes. The X-ray diffraction pattern showed an orientation of mesogen in EB-polymerized polymers.