STRUCTURES OF POINT INTEGER DISCLINATIONS AND THEIR ANNIHILATION BEHAVIOR IN THERMOTROPIC LIQUID-CRYSTAL POLYESTERS

A schlieren texture composed of integer strength point disclinations h as been observed in a thermotropic liquid crystal polymer. The directo r patterns about positive and negative disclinations are studied by op tical microscopy and scanning electron microscopy. Defects are located at the specimen-air interface and occur due to the different boundary conditions of the Liquid crystal at the air and glass interfaces. The annihilation behavior of these integer defects, created by a temperat ure-drop procedure from an initial isotropic state into the nematic st ate, was also investigated. It was found the relation between pair sep aration, D, and annihilation time, t(0), was D alpha (t(0) - t)(0.5), which was in good agreement with the recent scaling solution predictio n by Pargellis et al.(1)