Effect of polymer matrix on the magnetic properties of polymer bonded magnets filled Fe_3O_4 nanoparticles

摘要

The effect of binder on the magnetic properties of polymer bonded magnets (PBMs) was studied. Five PBMs containing 5 wt% of Fe3O4 nanoparticles were prepared by melt extrusion in a twin screw extruder. The selecting bonders were polypropylene, nylon 66, high impact polystyrene, polycarbonate and acrylonitrile butadiene styrene. Compression moulded samples were prepared. TEM images show a good dispersion for nylon 66 comparing to other nanocomposites. Dynamic intersection frequency (wc) which is related to crossing of G' and G" curves showed that there was a more homogeneity in the nylon 66 and PP nanocomposite comparing to that of other nanocomposites. The curves of saturation magnetization strength (Bs), residual magnetic flux density (Br), and coercive force (Hc) versus surface energy were plotted for different nanocomposites. The magnetic properties of nanocomposites had relationship with the rheological properties and also the surface energy of the matrices.