Synthesis and characterization of novel aromatic poly(amide–imide)s with alternate (amide–amide) and (imide–imide) sequences

Abstract

Diamine amic acids were synthesized by reacting aromatic diamines with 3,3′,4,4′-benzophenonetetracarboxylic dianhydride in dimethylacetamide and were characterized by melting points, elemental analyses, IR, 1H-NMR and HPLC. Poly(amide–amic acid)s were prepared by low temperature solution polycondensation of diamine amic acids with isophthaloyl chloride in dimethylacetamide. Poly(amide–imide)s with alternate (amide–amide) and (imide–imide) sequences were obtained by cycloimidization of poly(amide–amic acid)s with Et 3N–Ac 2O mixture in dimethylacetamide solution. They were characterized by solubilities, inherent viscosities, IR and 1H-NMR. Thermal properties of the polymers were measured by differential scanning calorimetry and thermogravimetric analyses.