DIELECTRIC-RELAXATION IN A NEW CYCLIC LIQUID-CRYSTALLINE OLIGOSILOXANE

Polysiloxanes with mesogenic side chains are suitable model compounds for the study of molecular dynamics. The first dielectric relaxation d ata are presented here for a cyclic oligosiloxane having a degree of o ligomerization of 5, a cyanophenylbenzoate group as the terminal dipol e, and a spacer lengths of 3. The phase sequence was determined by mea ns of X-ray diffraction, differential scanning calorimetry, and polari zing microscopy. Reasons for the strong dependence of physical propert ies on the degree of oligomerization are discussed.