CYANATED LIQUID-CRYSTALS WITH TRANS-STILBENE STRUCTURE - SYNTHESES AND THEIR CYCLOTRIMERIZATIONS

Liquid crystalline aromatic monocyanate (M) and dicyanates (D1 and D2) with trans-stilbene (-Ph-CH=CH-Ph-) structure were synthesized and th eir cyclotrimerization reactions were studied by differential scanning calorimetry and infrared spectroscopy. Monocyanate M underwent cyclot rimerization to yield a trimerized material with discotic properties. Dicyanate D2 and its cured product failed to exhibit any mesophase. In contrast, polycyclotrimerization of dicyanate D1 obtained a liquid cr ystalline thermoset with its schlieren texture prolonged over a wide t emperature range. (C) 1995 John Wiley and Sons, Inc.