In this study, N,N'-Bis [2-(methyl-3-(4-hydroxyphenyl) propanoate)] terephthaldiamide, as a new monomer based on amino acid containing chiral group was synthesized from the reaction of S-tyrosine methyl ester and terephthaloyl dichloride. A sequence of novel nanostructure aromatic optically active and eco-friendly poly(ester-amide)s (PEA)s based on tyrosine amino acid were synthesized by the solution polycondensation of this new diol and a number of aromatic diacid chlorides. One equimolar of synthesized diol monomer and one equimolar of different diacid chlorides were reacted at room temperature for 12 h and the resultanted mixtures were precipitated in methanol to obtain precipitate of nanostructure polymers. The resulting PEAs exhibited high thermal stability, good yields, and inherent viscosities ranging between 0.13 and 0.21 dL/g. Almost polymers showed good solubility and were soluble in polar solvents like NMP, DMAc, DMF, and DMSO at room temperature. The comparatively good solubility related to the amorphous structure and presence of aliphatic side chain and chiral center in backbone of polymers ,which hampered the packing of chains and reduce interchain contact. But in PEA7a we need to give a few heat for increase of solubility rate owing to its linear and symmetrical structure and a few crystalline regularity. All polymers were characterized by FT-IR, 1H-NMR, elemental analysis, specific rotation, 13C-NMR and characteristic by X-ray diffraction (XRD), thermogravimetric analysis (TGA) techniques and field emission scanning electron microscopy (FE-SEM) analysis that it can show polymers have nano structure with good dispersity. Based on the XRD data, PEA7b is totally amorphous, which dose not demonstrate any sharp diffraction peaks. While, the PEA7a is not quite amorphousand and show quantitative sharp diffraction peaks and afew crystalline regularity due to symmetrical structure of this polymer. So illustrate solubility less than PEA7b. Then compared results of solubility and X-ray diffraction (XRD) with same study of (PEA)s based on , N,N'-Bis [2-(methyl- 3-(4-hydroxyphenyl) propanoate)] isophthaldiamide.
