Magnetic and electromagnetic evaluation of the magnetic nanoparticle filled polyurethane nanocomposites

The magnetic and electromagnetic wave absorption behavior of a flexible iron-nanoparticle reinforced polyurethane nanocomposite is reported. Surface-initiated-polymerization (SIP) method was utilized to fabricate high-quality nanocomposites with uniform particle distribution and tunable particle loading (up to 65 wt %). The enhancement of coercive force is observed when the nanoparticles are embedded into the polymer matrix. Electromagnetic wave absorption performance at a discrete frequency as studied by metal-backed reflection loss indicates that the SIP nanocomposites can save the weight up to 50% compared to the composite counterpart with micron-size particles. © 2007 American Institute of Physics