synthesis and characterization of new heat-resistance polymers based on n- (4-carboxy phenyl) trimellitimide and aromatic diamines

five new aromatic poly(amide-imide)s (5a-e) were synthesized by direct polycondensationreaction of n-(4-carboxy phenyl) trimellitimide (3) with five aromatic diamines (4a-e) by usingtriphenyl phosphite in n-methyl-2-pyrrolidone (nmp) and pyridine at solution containingdissolved cacl2. all of the polymers were obtained in quantitative yields with inherentviscosities between 0.29-0.40 dl/g. the resulting poly(amide-imide)s were characterized withelemental analysis, viscosity measurements, solubility test, ft-ir spectroscopy, thermogravimetric analysis (tga) and differential thermal gravimetry (dtg). all of the polymers weresoluble in n-methyl-2-pyrrolidone (nmp), n,n-dimethylacetamide (dmac), n,n-dimethylformamide (dmf), dimethyl sulfoxide (dmso) at room temperature. n-(4-carboxyphenyl)trimellitimide (3) was prepared from the reaction of trimellitic anhydride (1) with 4-aminobenzoic acid (2) at room temperature and refluxing at 100-110°c in acetic acid as asolvent with a quantitative yield.