Preparation and Properties Magnetite/Polyimide Composites

To make the polyimide (PI) composite material having both heat resistance and magnetic permeability, Fe3O4/PI magnetic polyimide composite powder was synthesized by one-step solvothermal method. 4,4'-diaminodiphenyl ether (ODA) as monomers, ether anhydride polyamic acid (PAA) was designed and prepared by Fe3+ and polyimide precursor-polyamic acid triethylamine salt (PAAS) was reacted in a reactor, and the PI/Fe3O4 composite powders were synthesized under the condition of high temperature and high pressure. The obtained PI/Fe3O4 composite powders were analyzed by infrared spectroscopy, microscopic morphology and thermal properties. The morphology and structure of the samples were both characterized by scanning electron microscopy (SEM) and infrared spectroscopy (IR). The thermal properties of the composite microspheres were studied via thermogravimetric analysis (TGA) and the magnetic properties were determined by a vibrating sample magnetometer (VSM). The saturation magnetization decreases gradually, increasing the polyimide content, with a saturation magnetization of PI/Fe3O4 determined to be 20.29 emu/g.