LC-POLYIMIDES. 37. POLY(ESTER-IMIDE)S DERIVED FROM N,N′-BIS(4-CARBOXY-PHENYL)BIPHENYL-3,3′-4,4′-TETRA-CARBOXYLIC IMIDE AND VARIOUS α,ω-DIHYDROXYALKANES

A new imide monomer was prepared from ethyl-4-amino-benzoate and biphenyl-3,3′-4,4′-tetracarboxylic anhydride (BTCA). This new momoner was polycondensed with various α,ω-dihydroxyalkanes. The resulting poly(ester-imide)s, PEIs, were characterized by elemental analyses, inherent viscosities DSC-measurements optical microscopy, and X-ray measurements using synchrotron radiation. All PEIs formed a crystalline smectic H-phase in the solid state. Depending on the length of the spacer individual members of this series formed either an enantiotropic smectic-A phase, a monotropic smectic-A phase or no liquid crystalline phase at all. Long spacers and odd numbers of CH2-groups favored the formation of liquid-crystalline (LC-) phases.