Characterization on polystyrene/zinc oxide nanocomposites prepared from solution mixing

Polystyrene (PS)/zinc oxide (ZnO) nanocomposites were prepared by solution mixing, followed by film casting. The effects of ZnO nanoparticles on the physical properties of PS were investigated. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) showed that ZnO nanoparticles were homogeneously dispersed in the PS matrix. The introduction of 5 wt% ZnO increased slightly the glass transition temperature by 2.3°C. Thermal gravimetric analysis thermograms showed that the thermal stability of PS was enhanced with increasing ZnO content. Neither shift nor sharpening of absorption band was detected by infrared spectra. ZnO nanoparticles had little effect on the wide-angle X-ray diffraction (WAXD) pattern of PS. The transmittance of ultraviolet light was decreased with increasing ZnO content. PS/ZnO nanocomposites exhibited a small reduction in tensile strength and elongation to break. However, a significant enhancement in tensile modulus was achieved when 5 wt% ZnO was introduced. In the FESEM images of the tensile fractured surface, localized plastic deformation was observed for PS, while the site from which ZnO was pulled out was usually observed in the nanocomposites.