The reinforcing and toughening effects of PP blends were studied by the determination of the mechanical properties

dynamic mechanical analysis

DSC

as well as morphology and structures of the cross-sections

which were reinforced by nano-SiO2 rigid particles and toughened by EPDM elastic particles. It was shown that

the above two particles dispersed in PP matrix can increase not only the tougheness but also the strength and the modulus of PP at a great extent. As the blend ratio of PP/nano-SiO2/EPDM is 80/3/20

the two particles have the concerted toughening effect.Nano-SiO2 particles can also increase the crystallization temprature and crystallization rate of PP and decrease its size of spherulite. Nano-SiO2 particles are dispersed in the PP continuous phase in the form of conglomerates which are made up of 6～7 nano-SiO2 particles in average and have a good combination strength with PP matrix. The comprehensive properties of the PP/nano-SiO2/EPDM can match with the engineering plastics.