Improvement in the physicochemical properties of titanium dioxide by surface modification with 1H-1-carboxylate of isopropyl-imidazole and 3-aminopropyltrimethoxysilane: case study—as a filler in polylactic acid composites

This work presents the surface functionalization of titanium dioxide nanoparticles with 1H-1-carboxylate of isopropyl-imidazole and 3-aminopropyltrimethoxysilane. The surface and thermal properties of titanium dioxide are characterized by nuclear magnetic resonance, Fourier-transform infrared spectroscopy, zeta potential, X-ray diffraction, and differential scanning calorimetry. The functionalization mentioned above improves the dispersibility of titanium dioxide in polymeric matrices such as polylactic acid. Polylactic acid compounds are extruded with these nanoparticles; their crystallization capacity is studied by non-isothermal crystallization. The results obtained indicate the successful binding of organic structures to titanium dioxide. Likewise, the dispersion improves when the nanoparticle is silanized, reducing agglomeration when the isopropyl-imidazole 1H-1-carboxylate is bound to the organosilicon coating. DSC measurements show that isopropyl imidazole 1H-1-carboxylate adhered to the organosilicon coating exhibits excellent thermal stability up to 300 °C. Finally, the photo-degradation of the composites is studied by Fourier-transform infrared spectroscopy and atomic force microscopy, showing that the use of isopropyl-imidazole 1H-1-carboxylate inhibits the degradation of the polylactic acid composite compared to the pure polymer.