A comparative analysis of the structure of thermotropic liquid-crystallineboron-containing copolyethers and their organic analogs

Temperature variation of the structure of recently synthesized copolyethers , where (in contrast to the fully organic analogs) a columnar mesophase hav ing a two-dimensional pseudohexagonal packing of the conformationally disor dered chains was observed for the first time, was studied by X-ray diffract ion and DSC. The copolyethers of different composition were studied in the form of cold-pressed isotropic powders, having a nascent structure, and ann ealed samples. It was found that variation of the chemical structure allows different types of the ordered forms known in polymers to be observed acco rding to the scheme: crystal-S-H LC smectic-columnar mesophase-S-C LC smect ic-LC nematic-isotropic melt.