Effect of iron oxide nanoparticles on the morphological properties of isotactic polypropylene

Isotactic polypropylene (iPP) and iron oxide (Fe 3 O 4 ) nanocomposites were mixed by masterbatch blending technique in a single screw extruder machine. The concentrations of Fe 3 O 4 in the iPP/Fe 3 O 4 nanocomposites were 0.5, 1, 2, and 5% by weight. The influence of Fe 3 O 4 nanoparticles on the effectiveness of nucleation, morphology, mode of crystallization, and crystallinity of iPP were studied by differential scanning calorimetry (DSC) and polarized light microscopy (PLM). The introduction of Fe 3 O 4 nanoparticles in the iPP matrix inhibited the formation of β crystals, and caused a shift in the melting point to higher values. The magnitude of the shift was up to 20–21°C which indicates that using the masterbatch technique leads to an enhancement of the dispersion process of the Fe 3 O 4 nanoparticle and the formation of less agglomerates in the iPP/Fe 3 O 4 nanocomposites. The percentage crystallinity, X c , increased at the low cooling rates of 1 and 2°C/min. At higher cooling rates of 5, 10, and 20°C/min, the masterbatch technique produced nanocomposites of X c with nonuniform trends. The overall crystallization rate enhancement for the iPP/Fe 3 O 4 nanocomposites is attributed to the presence of Fe 3 O 4 nanoparticles as a nucleating agent which have no significant effect on the growth rate of iPP crystals.