Microstructure and properties of novel optically active poly(ester-imide)/TiO2 bionanocomposites containing natural amino acids moieties

Poly(ester-imide)s (PEI)s are a kind of non-vinyl polymers which can be prepared via step-growth polymerization. They contain ester and imide linkages in the polymer backbones and lately show significant applications, such as adhesives, printed circuit boards, membranes, and engineering thermoplastics. Synthesis of chiral polymers is an important field in macromolecular science, they have attracted a large deal of interest in the applications of fields for instance drug delivery, tissue engineering, dentistry and chiral stationary phases for resolution of enantiomers in chromatographic techniques due to their promising properties. In recent times, composites of biopolymers and bioactive inorganic materials have been extensively studied, due to a large variety of potential applications. They have been developed as bone-repairing devices because of their biocompatibility, bioactivity, and biodegradability. Several recent studies have suggested that some shapes of TiO₂ could act as a bioactive material in the sense that the material leads to an interfacial bonding to tissue by way of the formation of a biologically active hydroxyapatite layer on the implant surface. In this presentation I would like to show preparation of new optically active PEIs which were synthesized from the polymerization reaction of N,N´-(pyromellitoyl)-bis-L-amino acids diacid with diols using direct polymerization method. The optically active PEI/titanium dioxide (PEI/TiO₂) bionanocomposites were synthesized under ultrasonic irradiation. The formation of PEI was confirmed by ¹H-NMR, FT-IR, specific rotation and elemental analysis. The obtained polymers were optically active and thermally stable and due to present of amino acid group on the PEIs backbone, they could be categorized under environmentally friendly polymers The resulting bionanocomposites were characterized by FT-IR, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA) and their morpholo- - gy were investigated by scanning electron microscopy (SEM), scanning electron image (SEI), and transmission electron microscopy (TEM) analyses. The TEM, SEM and SEI results indicated that the nanoparticles were dispersed homogeneously in PEI matrix on nanoscale.