Preparation and characterization of optically active poly(amide-imide)/TiO2 bionanocomposites containing N-trimellitylimido-L-isoleucine linkages: using ionic liquid and ultrasonic irradiation

Abstract

In the present investigation, novel poly(amide-imide)/TiO2 bionanocomposites containing L-isoleucine moiety in the main chain were prepared via a simple and inexpensive ultrasonic irradiation process. Poly(amide-imide) as a source of polymer was synthesized by direct polycondensation reaction of N-trimellitylimido-L-isoleucine with 4,4′-diaminodiphenylsulfone in the tetrabutyl ammonium bromide/triphenyl phosphite as a green solvent system. Due to the high surface energy and tendency for agglomeration, the surface of TiO2 nanoparticles was modified with γ-aminopropyltriethoxyl silane. The resulting hybrid bionanocomposites were fully characterized by FT-IR spectroscopy, UV–vis spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM) and thermogravimetric analysis. Through TEM photographs, it can be found that the surface modified TiO2 nanoparticles with diametric size of less than 40 nm, uniformly dispersed in the obtained PAI matrix.