PROPERTIES OF SIDE-CHAIN LIQUID-CRYSTAL POLYESTERS CONTAINING CHIRAL GROUPS IN THE MAIN-CHAIN

The synthesis and investigation are reported for the phase behavior of a set of three liquid-crystalline side chain polyesters (SCLCPs), con sisting of aromatic diacids and diols bearing cyano biphenyl moieties in the side chain. The materials contain a chiral center in the main c hain and show a cholesteric phase Indicative of a helical order with a preferred twist. In addition, they exhibit T-g's below room temperatu re and smectic bilayer phases. Depending on the substitution pattern o f the aromatic core, S-C or S-A, phases are observed. These polymers were synthesized in a four-step synthesis, starting from available mat erials. The dielectric relaxation behavior and the pyroelectric respon ses of the three SCLCPs tend to conform to their respective structure.