UNUSUAL PHASE-BEHAVIOR OF A NEW LIQUID-CRYSTALLINE SIDE-GROUP POLYMER

The phase structure of a series of liquid-crystalline side group polymethacrylates with azo-groups in the mesogenic units was investigated by X-ray diffraction and differential scanning calorimetry. The influence of the spacer and tail length on the nature of the liquid crystal phase is discussed. For one polymer, depending on the annealing temperature, a phase transition from a metastable monolayer S(A) phase to a bilayer S(C) phase and to an unidentified phase, possibly crystalline, was found. This behaviour is discussed considering steric hindrance of the mesogenic side groups and the anisotropic conformation of the backbone,