Synthesis and properties of novel soluble and thermally stable optically active poly(amide-imide)s from N,N′(4,4′-xydiphthaloyl)-bis-L-phenylalanine diacid chloride and aromatic diamines

In this research work, 4,4'-oxydiphthalic anhydride (1) was reacted with L-phenylalanine (2) in acetic acid and the resulting imide-acid 3 was obtained in high yield. This imide-acid 3 was converted to diacid chloride 4 by reaction with thionyl chloride. The polycondensation reaction of diacid chloride 4 with several aromatic diamines such as 4,4'-sulfonyldianiline (5a), 4,4'-diaminodiphenyl methane (5b), 4,4'-diaminodiphenylether (5c), p-phenylenediamine (5d), m-phenylenediamine (5e), and 4,4'-diaminobiphenyl (5f) was performed by two conventional methods: low temperature solution polycondensation and short period reflux conditions. Several new thermally stable optically active poly(amide-imide)s with inherent viscosity ranging from 0.34-0.62 dL/g were obtained with high yield. All of the above polymers were fully characterized by H-1-NMR, FT-IR, elemental analyses and specific rotation techniques. Some structural characterizations and physical properties of this new optically active poly (amide-imide)s are reported.