LC-POLYIMIDES .5. POLY(ESTER-IMIDE)S DERIVED FROM N-(4-CARBOXYPHENYL) TRIMELLITIMIDE AND ALPHA,OMEGA-DIHYDROXYALKANES

N-(4-carboxyphenyl)trimellitimide was prepared from trimellitic anhydride and 4-aminobenzoic acid and esterified with methanol. Transesterification with alpha,omega-dihydroxyalkanes in the melt yielded a series of poly(ester-imide)s with varying spacer lengths. These poly(ester-imide)s were characterized by elemental analyses, inherent viscosities, differential scanning calorimetry measurements, wide angle X-ray spectroscopy powder and fibre patterns, including synchrotron radiation measurements at variable temperature, optical microscopy with polarized light, and thermogravimetric analyses. Poly(ester-imide)s with even-numbered spacers can form three different kinds of solid phase, including a smectic glass and a crystalline smectic phase. Fibre patterns of melt-spun fibres indicate a high degree of order for series of subsequent layers, even when any order inside the layers is lacking. Poly(ester-imide)s with odd-numbered spacers crystallize much more slowly and can be quenched from the isotropic melt, so that isotropic glasses can be obtained.