Chiral poly(amide-imide)/functionalized ZnO bionanocomposites containing L-alanine units

Organic-inorganic nanocomposites have attracted significant interest owing to unique combinaton desirable organic and inorganic properties.1-3 The inorganic nanoparticles into polymer matrix provied high-performance materials that find applications in many fields such as semiconductor, sensor, fuel cell, drug delivery, rechargable batteries, etc.4-6 In this study, optically active poly(amide-imide) (PAI)/ZnO hybrid bionanocomposite films with different weight percentages of ZnO nanoparticles were prepared via ultrasound-assisted technique. At the first a heteroaromatic diamine containing bulky phthalide group was successfully synthesized by a nucleophilic substitution reaction of phenolphthalein with p-bromonitrobenzene in the presence of K2CO3, followed by reduction of the dinitro compound by zinc dust and hydrochloric acid. Chiral diacid monomer, [N,N'-(4,4'-carbonyldiphthaloyl)]bis-L-alanine was synthesized through the reaction of 4,4ʹ-carbonyldiphthalic anhydride and amino acid L-alanine in acetic acid in high yield. The direct polymerization reaction of the synthesized diamine with chiral dicarboxylic acid was produced a new optically active PAI. The obtained PAI and different weight percentages of functionalized ZnO nanoparticles (2, 4, 6, 8 and 10 wt.%) were used to prepare PAI/ZnO bionanocomposite films through ultrasonication assisted process. The PAI/ZnO bionanocomposite films were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy and thermogravimetric analysis techniques.

Keywords:

Poly (amide-imide) , Bionanocomposite , L-Alanine , ZnO.