Construction and characterization of poly(amide-ester-imide) nanocomposites containing N-trimellitylimido-l-leucine toughened with a combination of bioactive surface-grafted TiO2

Abstract

This paper addressed production and characterization of novel type copolyester/titania (TiO2) nanocomposites (NCs). First, the surface of TiO2 was modified by chiral diacid monomer, N-trimellitylimido-l-leucine (TMIL) (1) as a coupling agent to form organomodified TiO2 (O-TiO2) nanoparticles (NPs). Fourier transform infrared (FT-IR) spectroscopy confirmed the presence of coupling agent groups on the surface. Thereafter, a novel chiral poly(amide-ester-imide) (PAEI) was synthesized by step-growth polymerization of diacid monomer 1 with diol, N,N′-(1,3,5,7-tetraoxo-5,7-dihydropyrrolo[3,4-f]isoindole-2,6(1H,3H)-diyl)bis(4-hydroxybenzamide) (2) via tosyl chloride, pyridine and N,N-dimethyformamide as a condensing agent. The incorporation of O-TiO2 NPs into the obtained PAEI provided an opportunity for the construction of polymer-based NCs with novel and powerful properties. The obtained NCs were premeditated using transmission electron microscopy (TEM), FT-IR spectra, thermogravimetric analysis (TGA), field emission scanning electron microscopy (FE-SEM), X-ray diffraction; also the optical properties of the NCs were studied using ultraviolet-visible spectroscopy. The TEM and FE-SEM results showed that the NPs were dispersed homogeneously in PAEI matrix on the nanoscale. TGA data confirmed that the heat stability of the aforementioned NCs in the presence of O-TiO2 NPs was improved.