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-(glycidyloxy)hexyloxy]2-naphthoate (Gly B) were obtained. Nematic elastomers were obtained by the crosslinking of Gly A with 2,4-diaminotoluene (DAT) and 1,10-decanedicarboxylic acid (SA). The liquid-crystalline behavior was investigated with differential scanning calorimetry, polarizing light microscopy, and X-ray diffractometry. Cholesteric mesophases were produced by the blending of different ratios of Gly A and Gly B, and these blends were then crosslinked with SA to produce nematic mesophases. (C) 2001 John Wiley & Sons, Inc.