Synthesis of novel poly(amide‐imide)s containing trimellitylimido‐ DL/L ‐alanine moieties via direct polycondensation

N‐Trimellitylimido‐DL and L‐alanine (3) were prepared from the reaction of trimellitic anhydride (1) with DL and L‐alanine (2) in N,N‐dimethyl formamide (DMF) solution at refluxing temperature. The direct polycondensation reaction of the monomers imide‐diacid (3) with 4,4′‐diaminodiphenylsulfone (4a), 4,4′‐diaminodiphenylmethane (4b), 1,4‐phenylenediamine (4c), 1,3‐phenylenediamine (4d), 2,4‐diaminotoluene (4e), and 4,4′‐diaminodiphenylether (4f) was carried out in a medium consisting of triphenyl phosphite, N‐methyl‐2‐pyrolidone (NMP), pyridine, and calcium chloride. The resulting poly(amide‐imide)s PAIs, with inherent viscosities 0.32–0.66 dL/g, were obtained in high yield. All of the above‐mentioned compounds were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these new optically active PAIs are reported.