Synthesis and characterization of rigid-chain liquid-crystalline polymers containing laterally attached side rods

A series of rigid-chain polymers containing different concentrations of lat erally attached side rods was synthesized. These polymers exhibited liquid crystallinity even up to a maximum side rod concentration of 20 mol %. The crystallinity of the polymers, however, decreased with an increase in the s ide-rod concentration. These polymers had lower dielectric constants compar ed with their parent polymers, that is, similar polymers, but without later ally attached side rods. A dielectric constant of 2.6 can be achieved by in corporating 10 mol % of laterally attached side rods, which is 0.5 lower th an that of its parent polymer. The reduction of dielectric constant may be attributed to low crystallinity as well as the less dense packing structure of the polymers induced by the incorporation of laterally attached side ro ds. This series of polymers also had good thermal stability. (C) 2001 John Wiley & Sons, Inc.