Comparative Analysis of Magnetorheological Effect in Soft Isotropic and Anisotropic Magnetoactive Elastomers

Magnetoactive elastomers based on polydimethylsiloxane and magnetic carbonyl iron microparticles with different distribution of the magnetic filler in the polymer matrix have been synthesized. Series of "soft" isotropic and anisotropic (synthesized in external magnetic field) samples without any low-molecular weight plasticizer and magnetic particles concentration 50-83 wt % have been obtained. Their viscoelastic properties in the absence of magnetic field and in the magnetic field with B = 1 T have been investigated. It has been shown that the values of the components of the dynamic shear modulus of anisotropic samples are more than twice higher in comparison with the isotropic analogs, their relative increase in the magnetic field being approximately the same. At the same time, the loss factor has been significantly decreased by the magnetic field application, reaching 0.1 for the composites with high content of the magnetic particles.