New liquid-crystal line thermosets from liquid-crystalline bisazomethynic epoxy resins with naphthylene disruptors in the central core

We synthesized novel epoxy-terminated monomers on the basis of imine groups with spacers of different lengths between mesogens and reactive groups and examined their mesogenic properties. Their reaction with primary aromatic diamines and tertiary amines was carried out to investigate the formation of liquid-crystalline thermosets. We explored how the curing conditions and the structures of the monomers and amines affected the formation of ordered networks. The special symmetry of a 1,5-disubstituted naphthalene unit in the central core led to nematic mesophases in the pure liquid-crystalline epoxy resins, and thermosets with locked nematic textures were obtained in all cases, regardless of the length of the spacer. (C) 2003 Wiley Periodicals.