LC-POLYIMIDES .29. CHIRAL AND THERMOTROPIC POLY(ESTERIMIDE)S BASED ON N-(4'-CABOXYPHENYL)TRIMELLITIMIDE AND NOVEL CHIRAL SPACERS

Starting from commercial S- or R-3-bromo-2-methylpropanol, several new spacer diols were prepared. These spacers were polycondensed with the acid chloride of N-(4'-carboxyphenyl)trimellitimide. The resulting poly(ester-imide)s were characterized by elemental analyses, viscosity measurements, H-1-NMR spectroscopy, DSC- and WAXD-measurements and optical microscopy. The poly(ester-imide)s derived from chiral, aliphatic spacers form layer structures in the solid state, but no liquid crystalline phase. With nonsymmetrical, nonchiral semialiphatic spacers, poly(ester-imide)s were obtained, which form a smectic E or H phase in the solid state, a smectic-A or -C phase in the melt, and a nematic phase, when the spacer possesses an odd number of CH2 groups. The polycondensation of a chiral semialiphatic spacer yielded thermotropic poly(ester-imide)s with either S- or R-configuration. WAXD patterns measured with synchrotron radiation at various temperatures proved that a layer structure exists in the solid state (smectic-E* or H*) and a chiral smectic-A* or -C* phase plus a cholesteric phase in the melt. A 1 : 1 blend of the S- and R-polyesters was also studied, but did not show unusual features. (C) 1995 John Wiley and Sons, Inc.