Sono-chemical synthesis is a fast procedure for preparing monodisperse nanoparticles. Magnetite nanoparticles were prepared via a sono-chemical reaction at room temperature. Fe3O4 nanostructures were then added to acrylonitrile-butadiene-styrene (ABS) copolymer. Nanocomposites are very appealing due to the fact that a small amount of nanostructure can lead to a great improvement in many properties such as mechanical and thermal properties. Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometer (VSM). The XRD pattern of nanoparticles is indexed as a cubic phase (space group: Fd-3m). Fe3O4 nanostructures exhibit a super paramagnetic behavior with a saturation magnetization of 54 emu/g and a coercivity of 11 Oe at room temperature. The effect of ultrasonic power on the shape and particle size was investigated and the result showed that at 150W by increasing power, the growth stage overcame the nucleation stage and nanoparticles with bigger diameters were obtained. The flame retardancy behavior of ABS-Fe3O4 was studied by UL-94 analysis.
