Magnetic Properties of Nanoparticle-Polymer Composites Prepared Using Surface Modification and Cross-Linking Reaction

摘要

Polymer composites of magnetic particles are widely used as microwave absorbers. An effective method for obtaining thinner microwave absorbers for device mounting is-increase the volume fraction of magnetic nanoparticles within the composites such that the permeability is enhanced. In this study, composites were prepared using magnetite nanoparticles surface-modified with 4-META (4-methacryloylioxyethyl trimellitate anhydride) and cross-linked with PEG-4SH (pentaerythritol tetra-polyethylene glycol ether with four thiol-modified terminals). These composites have a higher volume fraction of nanoparticles (up-62 vol%) and higher permeability than conventional epoxy resin composites. In addition, the prepared composites showed good microwave absorption properties (R.L. < - 20 dB) with a smaller matching thickness (d = 8.0mm) than the epoxy resin composites (d = 9.0mm).