Deformation Characteristics of Nano-SiO₂ Filled Polypropylene Composites

Surfaces of nano-silica particles can be effectively modified by means of irradiation graft polymerization. When polypropylene (PP) was compounded with these treated nanoparticles, an overall improvement in the mechanical properties of the composites at rather low filler content was acquired. The present work observed the deformation characteristics of the PP nanocomposites using transmission electron microscope. Due to the interfacial entanglement between the grafting polymers attached to the nanoparticles and the matrix polymer, the grafted nano-SiO₂ exhibits much greater extensibility in the composites than the nanoparticles as-received. It is believed to be the main cause of extensive plastic drawing of the matrix polymer surrounding the treated nanoparticles, and it provides the composites with higher static ductility.