Potentially eco-friendly poly (amide–ester–imide)/diacid-grafted titanium dioxide/modified montmorillonite nanocomposites containing natural amino acids

Abstract

The progress of organic/inorganic composite materials has been specifically trendy in the last decade. This article focused on the fabrication and characterization of nanocomposites (NCs) with two different nanoparticles. Poly(amide–ester–imide) (PAEI) matrix was prepared by reacting N,N′-(1,3,5,7-tetraoxo-5,7-dihydropyrrolo[3,4-f]isoindole-2,6(1H,3H)-diyl)bis(4-hydroxybenz-amide) with N-trimellitylimido-l-leucine (TML) via tosyl chloride, pyridine, and N,N-dimethylformamide as a condensing agent. The surface of titanium dioxide (TiO2) nanoparticles was modified with diacid TML. Diacid-grafted TiO2 (D-TiO2) was mixed with the obtained PAEI and sonicated to form a PAEI/D-TiO2 NC. Then, the surface of a sodium montmorillonite (MMT) was modified through intercalation with the cationic surfactant of l-leucine using an ion-exchange mechanism. PAEI/D-TiO2/organically modified montmorillonite composites at three different weight fractions of silicate layer were prepared via solution intercalation method. The spectral, morphological, and thermal properties of the aforementioned NCs were investigated in terms of several experimental techniques, including Fourier transform infrared spectroscopy, field-emission scanning electron microscopy (FESEM), X-ray diffraction, thermogravimetric analysis, and transmission electron microscopy (TEM). The obtained novel NCs improved thermal stability from neat polymer. Photographs showing TEM and FESEM results also illustrated that the nanofillers were rather uniformly distributed in the polymer matrix.