Synthesis and Characterization of New Optically Active Poly(amide-imide)s Based on N,N′-(bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic)-bis-L-2-aminobutyric acid

Five new optically active poly(amide-imide)s (PAIs) (6a–e) were prepared by direct polycondensation of the newly synthesized N,N′-(bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic)-bis-L-2-aminobutyric acid (4) with five various aromatic diamines (5a–e). Triphenyl phosphite (TPP)/pyridine (Py) in the presence of calcium chloride (CaCl2) and N-methyl-2-pyrrolidone (NMP) were successfully applied for the direct polycondensation reactions. These new polymers were obtained in quantitative yields with inherent viscosities between 0.22 and 0.45 dl/g and were characterized by elemental analysis, FT-IR, 1H-NMR spectroscopy, specific rotations, solubility tests and thermogravimetric analysis (TGA). These new polymers were readily soluble in various organic solvents such as NMP, N,N-dimetylacetamide (DMAc), N,N-dimethylformamide (DMF) and dimethylsolfoxide (DMSO). The diacide 4 was synthesized by the condensation reaction of bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride (BCDA) (1) with L-2-aminobutyric acid (2) in a acetic acid solution.