Liquid crystalline polymers having dimetric moieties as side chains

A new series of liquid crystalline polymers having dimetric moieties as side chains were synthesized. The polymers exhibited nematic and smectic A phases depending on the length and parity of the flexible spacers. As the length of the flexible spacer was varied, the nematic-isotropic transition temperature and the entropy change associated with the transition exhibited a remarkable odd-even effect, in which the even numbers exhibited higher values. The transition properties were compared with those of known liquid crystalline polymers and liquid crystal dimers. The dimetric moieties effectively affected the transition properties of the present polymers, and the odd-even effect was significantly greater than that of the known polymers. (C) 2009 Elsevier Ltd. All rights reserved.