In this project, a series of novel optically active and biodegradable polymers were prepared by direct polycondensation of the diacids based on pyromelliticdianhydride and various amino acids with new diamines under green condition. In the first part, the diamine compounds containing azo group were synthesized by reduction of dinitro with iron oxide hydroxide catalyst and hydrazine monohydrate and then polymers have been synthesized by direct polycondensation of prepared diamines and several optically active diacids. In the second part, the dinitro compound was reduced by Pd/C 10% and NH 2 NH 2 .H 2 O to give the diamin compound containing pyridine group. Optically active polymers containing pyridine moieties as side groups have been synthesis by polycondensation of synthesized diamine and several diacids based on amino acids. Chemical structures of new compounds were characterized by FT-IR, 1 H-NMR, specific rotation, elemental and thermogravimetric analysis (TGA) techniques, X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM) analysis. The FE-SEM and XRD results of the pure polymers indicated that the morphology of the obtained polymers contains nano spherical-shaped structure. In the third part, biodegradable poly(amide-imide) has been synthesized by direct polycondensation of the diacids based on pyromelliticdianhydride and amino acid with 4,4?-methylenebis(3-chloro-2,6-diethylaniline) under green condition. Finally, to obtain the homogeneous distribution of TiO 2 nanoparticles in polymer matrix, the surface of nanoparticles was modified with silane coupling agent (?-aminopropyltriethoxylsilane, KH550) and mixed with prepared polymer. In this way, the organic chains of silane coupling agents can accomplish steric hindrance between inorganic nanoparticles so the process of agglomerate formation is extensively reduced and the hydrophobicity of the surface of nanosized TiO 2 is obviously enhanced. poly(amide-imide)/TiO 2 nanocomposites (PAI/TiO 2 NC) were prepared via ultrasonic method. In addition, several different amounts of modified nanoclay with isoleucine amino acid, were added to the synthesized NCs. The resulting nanocomposites were characterized by FT-IR, XRD, TGA, FE-SEM and transmission electron microscopy (TEM). The FE-SEM and TEM results indicated that the TiO 2 particles were dispersed homogenously in nano scale in PAI matrix.