Abstract
Thermotropic Poly(ester-amide)s containing triethyleneglycol bis(4-carboxyphenyl) ether (PEG 3 ), o-Tolidine (OT) and various aromatic diols such as hydroquinone (HQ) and 4,4́-biphenol (BP) were synthesized by direct polycondensation with DPCP (diphenyl chlorophosphate) as direct condensation agent in the presence of pyridine and LiCl. The polymer structures were characterized by infrared spectroscopy and elemental analysis. The influence of structure, substituents and contents of various aromatic diols on the phase transitions were studied by Differential Scanning Calorimetry (DSC) and Polarized Optical Microscopy. These revealed that the structure and substituents of diols affected the mesophase while most of the synthesized polymers exhibit nematic mesophase. Addition of HQ decreased the melting temperature of the polymers, but, in contrast to others diols, did not affect thermal resistance.