Fe3O4/FePc/Pc magnetic composites with high mechanical properties and thermal stabilities by in situ preparation

A novel kind of organic-inorganic hybrid magnetic composites was prepared via in situ polymerization between Fe3O4/iron phthalocyanine oligomer (Fe3O4/FePc) hybrid microspheres and phthalocyanine (Pc) prepolymers in the presence of aromatic amine (3-APN). The Fe3O4/FePc hybrid microspheres exhibited loose interpenetrating network structures with diameters of 180+/-20 nm. Magnetic properties of final Fe3O4/FePc/Pc composites investigated by the vibrating sample magnetometer (VSM) indicated that the magnetic composites possessed considerable increased magnetism with the increase of Fe3O4/FePc content. The saturation magnetization of the magnetic composites with 15 wt.% content of Fe3O4/FePc was 3.500 emu/g (1,590 % increase) in comparison with that of composites with 5 wt.% Fe3O4/FePc content. Mechanical and thermal properties of the magnetic composites were also investigated. The flexural strength and modulus increase from 53.8 MPa and 3.47GPa in Pc composite to 70.4 MPa and 4.18GPa in Fe3O4/FePc/Pc composite with 15 wt.% Fe3O4/FePc content, leading to 30.8 % and 20.4 % increase respectively. The mechanical enhancements can be largely attributed to the good dispersion and finer compatibility of Fe3O4/FePc hybrid microspheres and Pc matrices, which were confirmed by SEM. Additionally, all the magnetic composites obtained demonstrated excellent thermal stability up to 550 C in air. Thus the Fe3O4/FePc/Pc magnetic composites with considerable magnetic properties as well as outstanding mechanical properties and excellent thermal stabilities can be used in advanced functional and structural materials.