High strength disclinations in liquid crystalline polymers with X-shaped two-dimensional mesogenic units

Textures of liquid crystalline polymers with two-dimensional mesogens have been investigated by using polarizing optical microscopy. Disclinations, strength |S| up to 3/2 and 5/2, were found easily in each sample. Occasionally, even high strength disclination pair can be found. These high strength disclinations are very sable in high temperature although they are energy unfavorable according to the theory of Nehring and Saupe. The rare textures may be ascribed to the unique shape of the molecular mesogenic units. The stability of the high strength disclination is attributed to the energy dispersion and high viscosity in polymer melt.