Preparation and characterization of polypropylene/silica nanocomposites by gamma irradiation via ultrafine blend

Polypropylene/silica nanocomposites were prepared by gamma irradiation via ultrafine blend so that the silica at 3% loading level can be well dispersed to polymeric materials for improving their mechanical performance. First, ultrafine blend processing in the melt state is an effective method for improving physical dispersion of nanosilica. Then irradiation technique generates firm and impervious joint between polypropylene and silica, due to the adding of the compatibilizer, maleic anhydride grafted polypropylene. The reaction of maleic anhydride groups with the hydroxyl groups on the surface of nanosilica was characterized by Fourier Transform Infrared Spectra (FTIR). Scanning electronic microscopy (SEM), X-ray diffraction analysis (XRD), differential scanning calorimeter (DSC) and polarized optical microscope (POM) were introduced to characterize the polypropylene/silica nanocomposites. Also the mechanical properties of the nanocomposites were evaluated by tensile strength, young's modulus and elongation at break, which showed good enhancement due to well dispersed silica and improving interface combination.