In this project, a new derived from tyrosine, N,N' -(pyromellitoyl)-bis-L-tyrosine dimethyl ester was prepared in three steps. The combination of three significant properties such as thermal stability, solubility and nontoxicity, biodegradability and biologically active due to the presence of L-tyrosine amino acid in the main chain cause which this diol can be regarded as non-toxic diphenolic monomer and may be employed as replacement for the industrially used diphenols in the design of biodegradable and biological polymers. Reaction of this optically and biologically active aromatic diol derived from tyrosine with diisocyanate and chiral diacids containing different amino acids lead to the formation of novel poly(urethane-imide) (PUI)s and pseudo-poly(amino acid)s with high thermal stability and biodegradable properties. The chemical structure of these compounds were confirmed by elemental analysis, FT-IR, 1 H-NMR, and 13 C-NMR spectroscopy, DSC and TGA thermal analysis, and specific rotation. In vitro toxicity and biodegradability behavior of the monomer and obtained polymers which were evaluated based on the growth of air-born bacterial and fungal on culture media and soil burial degradation. In addition, bio-nanocomposites titanium dioxide (TiO 2 ) and PUIs derived from tyrosine were prepared by capsulation method of nanoparticle titanium dioxide with surface active agent and dispersion in the polymer matrix because of improved properties such as high heat stability, UV-Vis absobance and photocatalysis properties of polymers via high-intensity ultrasound process. The PUI/TiO 2 bionanocomposites was characterized by Fourier transform IR spectroscopy (FT-IR), powder X-ray diffraction (XRD), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM) and UV-VIS spectroscopy. In last step of this project, bionanocomposites as suitable substrata from titanium dioxide were used for degradation of diazo dye (methyl orange) under UV-Vis irradiation.
