3-Glycidoxypropyltrimethoxysilane (GPS) was first used as a coupling agent to react with SiO2 nanoparticles to yield the modified SiO2 nanoparticles with epoxy groups on the surface of the nanoparticles (SiO2-GPS).In order to obtain the amine-riched SiO2 nanoparticles on the surface

hyperbranched poly-(ethylene imine) (HPEI) was mixed with SiO2-GPS and then a reaction occured between epoxy groups and amine groups

resulting to a poly(ethylene imine) grafted SiO2 nanoparticles (SiO2-GPS-g-HPEI).Subsequently

SiO2-GPS-g-HPEI was added into a blend of polypropylene and polyproplyene- grafted -maleic anhydride (PP/PP-g-MAH) to enhance the strength of PP.The modified SiO2 nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR)

thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM)

respectively.The results showed that GPS and HPEI had been grafted onto the surface of SiO2 nanoparticles

which had well dispersity in matrix of PP.After blending by Haake Rheomix600 OS viscometer

the blend was molded into a sheet by compression

and testing specimens were cut from the molded sheets by a die cutter.The samples were characterized by tensile strength and notched impact strength.The results of scanning electron microscopy (SEM) revealed the tough fracture.The torque curve of ternary blending (on behalf of the viscosity) was increased

indicating that the reaction happened in blending.The notched impact strength of PP/PP-g-MAH increased by 96.3% compared to pure PP after adding 2% SiO2-GPS-g-HPEI.Moreover

tensile properties of the nanocomposites were also enhanced.