Poly(amide-imide-esters) derived from asymmetric diacids and diphenols containing silicon or carbon as central atom. Synthesis, characterization and thermal studies

Abstract: Poly(amide-imide-esters) (PAIEs) were obtained from a series of unsymmetrical diacids containing an amide and an imide group in the structure and diphenols containing Si or C as central atoms. The unsymmetrical diacids were obtained from trimellitic anhydride chloride which reacted with p-aminobenzoic acid, followed by the reaction of the resulting amide–imide acid with an amino acid such as glycine, L-alanine, L-valine, and p-aminobenzoic acid. The obtained monomeric diacids were polymerized with bisphenol-A and with the analogous bisphenol containing silicon as central atom to give PAIEs. These polymers were characterized by spectroscopic methods and their main properties such as solubility, molecular weight, glass transition, and thermal stability were studied in correlation with the presence of C or Si atoms in the bisphenol segment and with the amount of aromatic units in the diacid segment.