Abstract: In this paper, poly(butyl acrylate) (PBA) was grafted onto the suface of nano silicon dioxide particles through surface-initiated atom transfer radical polymerization (ATRP). The results of FT-IR spetra, transmission electron microscope (TEM) and gel permeation chromatography (GPC) measurements show that we can prepare well dispersed nano SiO2-g-PBA composited particles by means of ATRP method. Moreover, the effects of nano silicon dioxide (SiO2) particles and nano SiO2-g-PBA composited particles on the of polyoxymethylene (POM) were studied by means of mechanical properties test, scanning electron microscope (SEM) and TEM. The results show that nano SiO2 particles conglomerate in POM matrix, while nano SiO2-g-PBA composited particles can be well dispersed in POM, leading to better notched impact strength of POM/ SiO2-g-PBA composite than that of neat POM or POM/ SiO2 composite. When the content of nano SiO2-g-PBA composited particles is 2%, the impact strength of composited material is 8 times than that of pure POM, and tensile strength is also imoproved .

Key words: atom transfer radical polymerization, surface grafting, nano silicon dioxide, nano SiO2-g-PBA composited particles, polyoxymethylene, mechanical properties