Composite polymeric foams produced by using magnetic field

Polymeric foams with different concentrations of Fe particles were prepared. The effects of magnetic field (MF) during the foaming process was analyzed. Mechanical properties and cell morphology of samples foamed with and without the application of the MF were compared. As revealed by optical and electronic scanning microscopy the magnetic field induced an alignment of Fe particles. The compressive mechanical tests performed on the foams showed an enhancement of the properties with the increase of particles concentration. When the iron particles were aligned by the magnetic field an improvement of the mechanical properties in the alignment direction was measured when compared to the samples with the same particle content. The effect of particles alignment was evident starting from low weight concentrations (5%wt). The mechanical behavior of the samples prepared by using the magnetic field was strongly anisotropic: in the field direction the mechanical behavior was higher than that in the orthogonal direction. The development of cellular structures produced by applying a magnetic field during the foaming process allows the design of anisotropic structures with cell morphology and mechanical properties tailored for desired directions.