Preparation and characterization of polystyrene-based magnetic nanocomposites. Thermal, mechanical and magnetic properties

In this paper we report results on both material preparation and characteri zation of a polystyrene-based magnetic nanocomposite material. CoFe2O4 mine ralized sulfonated polystyrene was prepared by in-situ precipitation and ox idation of Co+2 and Fe+2 within a sulfonated polystyrene resin. The magneti c oxide particles of nanometer size were characterized by wide angle X-ray diffraction (WAXD). Polystyrene-based composite films were obtained by disp ersion of the finely milled mineralized resin in a polystyrene matrix from the melt state (compositions ranging from 0 to 50 wt% of mineralized resin) . The thermal and mechanical properties of the nanocomposite films were det ermined by TGA, DSC, and stress-strain testing. The magnetic characterizati on of the samples was also performed. No significant changes in thermal sta bility, glass transition temperature or mechanical properties of the polyst yrene matrix occur as a consequence of the content in mineralized resin. Th ese results show that the filler acts as an inert diluent for the polymer m atrix. On the other hand, the magnetic characterization of the samples reve als the presence of nanoparticles with diameters ranging from 3 to 8 nm, sh owing, at room temperature, coercive field values of around 800 Oe and satu ration magnetization between 120 and 420 emu/g. The combination of these pr operties suggests the use of these systems in the preparation of magnetic r ecording materials with high recording density.