SYNTHESIS AND THERMAL-PROPERTIES OF SIDE-CHAIN LIQUID-CRYSTALLINE POLY(GLYCIDYL ETHERS) WITH RACEMIC AND CHIRAL BACKBONE

Oxiranes bearing a 4-cyanobiphenyl-4'-oxy mesogenic group with spacers of different length have been synthesized from glycidyl p-toluenesulfonate or epichlorohydrin (racemic or optically active). These monomers were polymerized with anionic initiators (CsOH, tBuOK (a))) or a chelate initiator (A1Et(3)/H2O/acetylacetone (a))). A transfer of chirality from the polymer backbone to the mesophase is observed for polyethers with a short spacer. A cholesteric phase is observed for the optically active polymer while the racemic polymer is nematic. Increasing the length of the spacer leads to a smectic mesophase. However, in that case, the effect of the chiral centre of the polymer backbone on the mesomorphous properties is not detected.