Chapter 37 - Preparation of Polybenzoxazine-Ni-Zn Ferrite Nanocomposites and Their Magnetic Property

Abstract

This chapter reports the preparation and characterization of polybenzoxazine-Ni-Zn ferrite nanocomposites. Ni-Zn ferrites (NZFs) are magnetically soft materials and exhibit versatile properties such as high saturation magnetization, low coercivity, high resistivity, and low dielectric losses. These properties make them potential candidates for numerous high frequency applications such as inductance coils, transformer cores, antennas, and microwave absorbers. Ferrite coatings and thin films are frequently used as the magnetic layer of a magneto-optical recording medium. Nanostructured NZF and their composites have generated a great deal of interest in recent years. This is due to their capability to exhibit certain superior properties that could lead to novel applications in the field of high frequencies, biosensors, targeted drug delivery, catalysts, pigments, etc. Polybenzoxazine, a newly developed phenolic resin, is chosen as the polymer matrix to prepare polybenzoxazine-NZF nanocomposites. Though common phenolic or epoxy resins have myriad applications in diverse fields, a number of shortcomings are also associated with these materials. Some of the limitations include brittleness, poor shelf life, use of acid or base catalysts, release of byproducts, formation of micro voids during curing, and so forth. To overcome these limitations, a new type of addition-cure phenolic system, polybenzoxazine, is recently developed. In this chapter, preparation of NZF nanopowders using aqueous solution-based precursor methods is described. These synthesized NZF nanoparticles are blended with difunctional benzoxazine monomers with various ratios by a solvent casting method.