Synthesis and characterization of novel poly(ester-imide)s containing chiral centers

This Thesis project describes the preparation of a series of novel Poly(ester-imide)s containing chiral centers, and their characterization for liquid crystallinity. The synthetic approach towards the incorporation of the chiral centers in the polymer backbone involved the reaction of α-amino carboxylic acid with trimellitic anhydride (TMA) or pyromellitic dianhydride (PMDA) to prepare the imide dicarboxylic acid monomers, which were melt polymerized with the respective diols containing two, three and five to ten methylene groups to obtain the Poly(ester-imide)s. The monomers were characterized by infrared spectroscopy, elemental analysis and polarimetry. Characterization of the polymers was done by dilute solution viscosity, infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry and polarizing light microscopy. Inherent viscosity values ranged from 0.27 dl/g to 0.99 dl/g. The glass transition temperature values ranged from 11 °C for ten to 104 °C for two methylene groups in the polymer backbone, for the series containing the TMA molecule. Thermal decomposition occurred at temperatures well above 350 °C, for all of the polymers. No melting or crystallization transition was observed for this series of Poly(ester-imide)s. Polarization light microscope studies show very low birefringence. No evidence of mesomorphism was seen.