The Synthesis, Characterization And Properties Of Hyperbranched Polyesters Functionalized With Liquid Crystals

A series of mesogenic units (nOCB) with different length of flexible spacer were synthesized from 4-hydroxy-4 ' -cyanobiphenyl and n-Chloroalkylol. The 86% yield of the reaction for 2OCB was achieved in ethanol, and the yields for 3OCB and 6OCB in acetone were 75% and 73%, respectively. The structures of these mesogenic molecules were characterized by FT-IR and ¹HNMR. Tm and Ti were determined by DSC. The schlieren textures of these mesogenic molecules were observed by POM that indicated they were nematic liquid crystals.The hyperbranched polyesters with terminal -COOH groups (HBP) were prepared from succinic anhydride and glycidol. The effects of reactant ratio and the feed method on the molecule weight of HBP were studied. The structure of HBP was characterized by FT-IR, ¹HNMR and ¹³CNMR. The molecule weight and the molecule weight distribution of HBP relative to PS were 2213 g/mol and 1.69, respectively, as determined by GPC.The -COOH groups on the HBP were transformed into -COCl by the reaction of HBP with thionyl chloride, and they were used for preparing the mesogenic molecule functionalized hyperbranched polyesters (HBP-nOCB) with the mesogenic units located on the periphery of HBP. The structures of HBP-nOCB were characterized by FT-IR, ¹HNMR, ¹³CNMR and GPC. The amount of mesogenic units in HBP-nOCB was 60%, 40% , 50% and 56%, 37%,43% as calculated by ¹HNMR and UV spectra, respectively. These HBP-nOCB liquid crystal macromolecules exhibited...