Synthesis of Liquid Crystalline Polyesterimides by Melt Polymerization and lts Application to Polymer-Dispersed Liquid Crystal

摘要

N-(4-Carboxyphenyl)trimellitimide(DAI)was synthesized from trimellitic anhydride and p-aminobenzoic acid by a one-step reaction utilizing m-cresol as a solvent.DAI was reacted with hexanediol and nonanediol to give bishydroxyhexyltrimellitimide (BHHI) and bishydroxynonyltrimellitimide (BHNI), respectively. Thermotropic liquid crystalline polyesterimides with BHHI and BHNI as a mesogenic group and 6 and 9 methylene units as a spacer were synthesized by a direct melt-polymerization method similar to the one used in the preraration of commercial polyester. Polyesterimides were characterized by IR, ~1H-NMR, DSC, and a polarized optical microscope.Their application as a matrix (binder) of polymer-dispersed liquid crystal (PDLC) was investigated with 4-heptyloxybenzoic acid as a low molecular wgight liquid crystal (LMWLC).From the PDLC experiment, polyesterimides were found to be useful as a matrix for the high-temperature PDLC above 100 deg C.