Nanocomposites of polypropylene/nano titanium dioxide: effect of loading rates of nano titanium dioxide

Abstract

TiO2 filled Polypropylene (PP) nanocomposites were prepared with a single screw extruder and then by injection molding of the blends. Water absorption, density, mechanical properties, morphological characterization, FTIR analysis, and the thermal stabilities of the nanocomposites were investigated. The results showed that water absorption decreased and density increased as the amount of nano-TiO2 added increased. The mechanical properties improved for all formulations with the addition of nano-TiO2, except for the tensile modulus of elasticity and the izod impact strength. Thermogravimetric analysis (TGA) indicated that the thermal stability of the nanocomposites improved as the amount of nano-TiO2 increased. The melting and decomposition peaks of DTA increased as nano-TiO2 was added. The differential scanning calorimetry (DSC) results showed that the melting temperature (Tm) increased with the addition of nano-TiO2. Scanning electron microscopy (SEM) images of the nanocomposites showed uniform dispersion for 0.5, 1, and 2 % TiO2, but some agglomerations were found on the surfaces and in the fractured sides of the nanocomposites with 4 % TiO2. The agglomerates were determined by SEM mapping. The changes in the chemical structure of the nanocomposites were determined with Fourier transform infrared (FTIR) spectroscopic analysis. The FTIR results showed that the chemical structures of the composites were similar and that there were no major differences between the composites.