Observation of disclinations and optical anisotropy in a mesomorphic copolyester

We report observations carried out on a thermotropic opolyester which had been polymerized by the manufacturers with the random addition of aromatic groups into the conventional poly(ethylene terephthalate) chain. At elevated temperatures the material exhibits complex anisotropic effects in the quiescent mesomorphic state which are observed to be frozen into the material at room temperature. The copolyester is sensitive to surface effects and is possibly influenced by magnetic fields. Using the latter technique we were able to orient the polymer in a manner which enabled us positively to identify within the material the existence of disclinations with strengths of +1. Finally surface replica electron microscopy revealed a morphological texture that complimented and extended that deduced from the optical studies