Synthesis and Properties of New Liquid Crystals as Curing Agents for Epoxy Resins

A novel class liquid crystalline epoxy resins was synthesized by reacting the diglycidyl ether of bisphenol A (DGEBA) with three new liquid crystal diols, 4,4`-di-N-](6-hydroxy hexoxy)-3-pyridyl methylidene [amino phenyl benzamide, 4,4`- di-N-](6-hydroxy butoxy)-3-pyridyl methylidene[amino phenyl benzamide, and 4,4`- di-N-](6-hydroxy etoxy)-3-pyridyl methylidene[amino phenyl benzamide, contain azomethine groups. The new liquid crystals were characterized by Fourier transformed infra-red (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy. Flexibility and adhesion properties were then investigated for the cured resins based on new azomethine mesogenic diols. The cured polymers were found to exhibit high flexibility and good adhesion properties compared to ordinary amine systems.