Preparation of composite particles coated with two kinds of solid powders by semi-chemical recycle method

Polymer microspheres coated with two kinds of solid powders were prepared by the semi-chemical recycle method of waste plastics. Magnetite (Fe3O4) and silicon carbide (SiC) were added as solid powders so as to give thermal and electric conductivity and magnetization. Waste expanded polystyrene was used as raw materials of polymer matrix of composite particles. In the experiment, the oil phase dissolving expanded polystyrene was dispersed to form the O/W dispersion in the continuous water phase in which polyvinyl alcohol and magnetite powders were added. And then, silicon carbide powder was added into the O/W dispersion. Composite particles prepared had the structure that a polymer particle was covered with two kinds of solid powders. The amount of each solid powder adhered on the surface of polymer microsphere was strongly affected by an addition time of silicon carbide powder. Furthermore, the gradient adhesion layer due to two solid powders was found to be formed on the surface of polymer microsphere. C 2006 Springer Science + Business Media, Inc.