Silica nanoparticles filled polypropylene: effects of particle surface treatment, matrix ductility and particle species on mechanical performance of the composites

The current paper is a continuation of the authors' work on mechanical performance of nano-silica/polypropylene (PP) composites. Unlike the fumed nano-silica used in the previous studies, precipitated nano-silica is employed in the present investigation. The results indicate that graft polymerization onto the precipitated nano-silica (that has been successfully applied to the surface modification of fumed nano-silica) is still an effective method to pre-treat the particles, which leads to an overall improvement of the composites properties. In addition to the grafting polymers covalently attached to the nanoparticles, matrix ductility and nanoparticles size are important factors that influence the extent of performance enhancement of the composites. In the case of suitable combination of these factors, the positive effect of the nanoparticles can be maximized.