LC-POLY(ESTER-AMIDE-IMIDE)S DERIVED FROM TRIMELLITIC ACID AND 4-AMINOBENZOIC ACID

A new mesogene diester based on phenyltrimellitimide was synthesized a nd used as a condensation monomer in combination with a number of alip hatic diols to render novel poly(ester-amide-imide)s (PEAIs). The melt polycondensation method provided polymers of moderate inherent viscos ity, that were characterized by elemental analyses, differential scann ing calorimetry, X-ray diffractometry, including synchrotron radiation measurements at different temperatures, optical microscopy with polar ized light and thermogravimetric analysis. The glass transition temper atures (T-g) lie in the range 100-130 degrees C, which means a substan tial improvement relative to analogous poly(ester-imide)s (PEIs). All the novel PEAIs are thermotropic materials that show a mobile LC-mesop hase above the melting temperature. By combining microscopic observati ons with X-ray diffraction diagrams, the mesophases could be identifie d as smectic-A phases. PEAIs with even-numbered spacers are semi-cryst alline in the solid slate, while those with odd-numbered spacers can f orm a solid smectic glass phase, i.e, a frozen smectic-A phase, upon r apid cooling from the melt. Copyright (C) Elsevier Science Ltd.