Structural features of bionanocomposite derived from novel designed poly(ester-imide) based on natural amino acids with hydroxyl segments tailored for better dispersion of TiO2 nanofiller

Deliberately inorganic nanoparticles (NP)s in polymer matrices significantly affect their characteristics and therefore their applications, but key factor to achieve the expected efficiency is well dispersion of the NPs in polymer matrix. The work presented here deals with the polymerization of amino acid-based monomer to synthesize optically active poly(ester-imide) (PEI) with hydroxyl terminated groups, using tosyl chloride/pyridine/N,N-dimethylformamide system as a condensing agent. The synthesized polymer was used for the preparation of bionanocomposite (BNC) containing modified titanium dioxide (TiO₂) NPs using ultrasonic irradiation. With the aim of γ-amidopropyl-triethoxylsilicane as a coupling agent, the surface of nanoscale TiO₂ was modified to decrease aggregation of the NPs in polymer matrix. The obtained PEI/TiO₂ BNCs were characterized with fourier transfer infrared (FT–IR), thermogravimetric analysis, field emission scanning electron microscopy (FE–SEM), X-ray diffraction and transmission electron microscopy (TEM) techniques. Morphology study of resulting PEI/TiO₂ BNCs by FE–SEM and TEM analyses demonstrated that the hydroxyl-terminated polymer chains reduced aggregation of the NPs and thus lead to better dispersion of the NPs in the polymer matrix.