Key Words:Copolymers;Atomic force microscopy - Dispersions - Nanostructured materials - Polystyrenes - Rheology - Transmission electron microscopy - Ultraviolet radiation;Ethylene-vinyl acetate copolymers - High-impact polystyrene (HIPS) - Rosand Precision rheometer
Abstract:TiO<inf>2</inf> nanoparticles were introduced into high-impact polystyrene (HIPS) in the form of a master batch in which TiO<inf>2</inf> was predispersed in composites of HIPS and ethylene-vinyl acetate copolymer (EVA) by melt compounding. The resulting materials were analyzed with a Rosand Precision rheometer, transmission electron microscopy, atomic force microscopy, and ultraviolet-visible light spectrophotometry. The results showed that the introduction of TiO<inf>2</inf> nanoparticles into HIPS influenced the apparent viscosity of the composites to a rather small extent. The addition of EVA could regulate the rheological behavior of the HIPS/TiO<inf>2</inf> master batch greatly. EVA helped the dispersions of the agglomerates of TiO<inf>2</inf> nanoparticles in the flow; this was featured by the distinct yielding in the flow after the introduction of EVA, as well as the large change in the non-Newtonian indices. The dispersions of the HIPS/TiO<inf>2</inf> master batch in the HIPS matrix were improved greatly by the addition of EVA. TiO<inf>2</inf> nanoparticles were dispersed randomly in HIPS/EVA/TiO<inf>2</inf> nanocomposites. The dispersion improvement of the HIPS/EVA/TiO<inf>2</inf> master batch was also proved by atomic force microscopy and ultravioletvisible spectroscopy investigations. The mechanical properties of HIPS/EVA/TiO <inf>2</inf> nanocomposites with low TiO<inf>2</inf> contents were slightly higher than those of pure HIPS. &copy; 2006 Wiley Periodicals, Inc.
Volume:100
Issue:6
Translation or Not:no