New cholesteric liquid-crystal epoxy resins derived from 6-hydroxy-2-naphthoic acid

Liquid-crystalline epoxy resins were synthesized from 6-hydroxy-2-naphthoic acid, which was used as a mesogenic component, with phenylhydroquinone or isosorbide and via a further reaction with (6-bromo-1-hexyl)glycidylether, which was used as a flexible spacer. In this way, phenylhydroquinone-bis-6- [6-(glycidyloxy)hexyloxy]2-naphthoate (Gly A) and isosorbide-bis-6-[6-(glyc idyloxy)hexyloxy]2-naphthoate (Gly B) were obtained. Nematic elastomers wer e obtained by the crosslinking of Gly A with 2,4-diaminotoluene (DAT) and 1 ,10-decanedicarboxylic acid (SA). The liquid-crystalline behavior was inves tigated with differential scanning calorimetry, polarizing light microscopy , and X-ray diffractometry. Cholesteric mesophases were produced by the ble nding of different ratios of Gly A and Gly B, and these blends were then cr osslinked with SA to produce nematic mesophases. (C) 2001 John Wiley & Sons , Inc.