Synthesis and characterization of thermotropic liquid crystalline poly(ester imide)s

Abstract

Two closely series of poly(ester imide)s had been synthesized by solution polycondensation of p-phenylenebis(trimellitate) dianhydride with aliphatic diamines. The differential scanning calorimetry (DSC) traces of the most poly(ester imide)s exhibited two endotherms representing the solid state to anisotropic phase transition (Tm1) and the anisotropic to isotropic melt transition (Tm2), respectively. Observation under polarizing microscope and wide-angle X-ray diffraction (WAXD) measurements suggested that the anisotropic phase formed above the melting points (Tm1) had a smectic character. The thermogravimetric analyses (TGA) revealed that the thermal stabilities of the poly(ester imide)s were up to 350°C. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 211–218, 1999