DYNAMIC MECHANICAL ANALYSIS OF POLYMER COMPOSITES WITH DIFFERENT TYPES OF MAGNETIC FILLERS

Polymer bonded magnets (PBMs) have shown great potential for applications in various industries. Many combinations of thermoplastic polymer matrices and fillers can be successfully produced by injection molding. The aim of this study is to synthesize Nd-Fe-B or barium ferrite - polymethylmetacrilate (PMMA) PBMs with optimal mechanical and magnetic properties. The synthesized Nd-Fe-B/PMMA and barium ferrite/PMMA composites are compared and analyzed under microstructural (SEM), thermal (DSC, TGA, DMA) and magnetic (SQUID) aspects. Highly sensitive characterization methods such as DMA reveal the differences between the samples in terms of dynamic mechanical properties. In addition, high-resolution SQUID measurements will show the magnetic superiority of Nd-Fe-B/PMMA composites. Furthermore, hybrid magnetic composites (Nd-Fe-B/barium ferrite/PMMA) show the best performance in dynamic mechanical properties compared to single magnetic composites, while the magnetic properties are between Nd-Fe-B/PMMA and barium ferrite/PMMA composites. The analysis of the SEM images of the fracture surface of the PBMs shows the formation of a stable and homogeneous composite material. Besides the high potential for many applications, the investigated composites are a good basis for further research activities in terms of particle size distribution, particle coating, coupling agents, stabilizers and final processing.