In this investigation, the synthesis and characterization of novel chiral and nanostructured poly(amide-imide)s (PAIs) have been reported. Chiral diacids monomers were prepared from the reaction of pyromellitic dianhydride and different natural amino acids such as L-valine, L-phenylealanine, L-alanine, and L-isoleucine. Then direct polycondensation reaction of these optically active diacids with 4,4?-methylenebis(3-chloro-2,6- diethylaniline) was performed using molten tetrabutylammonium bromide as a green ionic medium in the presence of triphenyl phosphite as an activating reagent. PAIs were obtained in good yields and moderate inherent viscosity in the range of 0.43-0.49 dL/g. The obtained polymers were characterized by means of speci?c rotation experiments, 1H-NMR, FT-IR, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), thermogravimetric analysis (TGA), and elemental analyses techniques. The results from FE-ESM and XRD showed that the obtained PAIs have nanostructure (with particle size in a range of 47-130 nm before sonication and 49-74 nm after sonication process) and amorphous morphology. TGA of the PAIs showed that the obtained polymers have good thermal stability. In the second project, a novel chiral PAI based bionanocomposites (BNC)s have been successfully prepared via ultrasonic irradiation method using zinc oxide (ZnO) nanoparticles functionalized by ?- aminopropyltriethoxysilane as a coupling agent to decrease aggregation of nanoparticles in polymer matrix. The resulting BNCs were characterized by several techniques including FT-IR, XRD, and TGA. Also their morphology was investigated by FE-SEM and transmission electron microscopy (TEM) analysis. TEM and FE-SEM images revealed that ZnO nanoparticles were good dispersed in nanosize in PAI matrix with particles size between 15-25 nm. TGA data showed an improvement of thermal stability of new BNCs in comparing with the pure PAI. In the end project, biological and biodegradability properties of synthetic polymers and monomers were investigated. In vitro fungal colonization and weight loss of the synthetic polymers showed that PAIs are probably biologically active and biodegradable under natural environment.
