The toughening of semi-crystalline polymers with inorganic nanofiller is very important in the practical applications of such polymers. In this study, we successfully fabricated the surface attaching silica nanoparticles of silica nanofibers (SiO2@SNFs) from the calcination of electrospun poly(vinyl pyrrolidone)/tetraethyl orthosilicate/silica nanoparticle (PVP/TEOS/SiO2) nanofibers for the toughening of polypropylene (PP). The SiO2@SNFs had a nanoprotrusion structured surface, and the degree of surface nanoprotrusion of the silica nanofibers (SNF) can be adjusted via the incorporated SiO2 nanoparticle content of the SiO2@SNFs. The effects of the SiO2 content of the SiO2@SNFs on the crystallization
behavior, relative b-form crystal content, and mechanical properties of PP were investigated with polarized optical microscopy, X-ray diffraction and notched Izod impact test methods. By comparison with SNF, the SiO2@SNFs showed greater improvements in the impact strength and heterogeneous crystal nucleation of PP at the same loading content of filler. The impact strength of PP/SiO2@SNFs at a loading of 2 wt% of SiO2@SNFs with 9 phr (SiO2/TEOS ? 9/100) of SiO2 nanoparticles was improved by
about 1.9 and 1.4 times that of neat PP and PP/SNFs composite (2 wt% of SNFs), respectively. However, the crystallinity, relative b-form crystal content, and tensile strength of PP/SiO2@SNFs were almost independent of the SiO2 nanoparticle content of the SiO2@SNFs. Our results demonstrated that these
nanoprotrusion surface structured silica nanofibers can be used as a novel nanofiller for improving the toughening of PP.