In this study, effects of surface modification of calcium carbonate (CaCO3) nanoparticles with a single-layer of stearic acid were investigated on dispersion in polypropylene (PP) matrix. Two kinds of CaCO3 nanoparticles (monolayer-coated and uncoated) were used to investigate this effect. All combinations were mixed in a co-rotating twin screw extruder and then were injection molded. After breaking the injection molded parts in liquid nitrogen, effect of surface modification of nanoparticles on their dispersion in the PP matrix was investigated using a field emission scanning electron microscope (FESEM). The results showed good agreement between the measurements made with the TGA analysis and the existing theories. The surface modification of calcium carbonate nanoparticles using a single layer of stearic acid also had an effective influence on improving distribution and dispersion of nanoparticles in the PP matrix.
