Liquid crystalline side group polyesters with a systematic variation of main chain and side group spacer length

To investigate the influence of a systematic variation of the length of main chain and side group spacers on the thermal phase behaviour four homologous series of liquid crystalline side group polyesters with 4-(phenylazo)azobenzene moieties as mesogenic side groups have been prepared and characterized. The polyesters exhibit smectic and/or nematic phases. The mesomorphic properties were studied by using optical polarizing microscopy, differential scanning calorimetry (DSC) and X-ray diffraction. Packing models of the low ordered smectic phases have been derived from X-ray data.