Mechanical Properties of Anisotropic Magnetic Elastomers

Abstract

Anisotropic magnetically active elastomers based on polydimethylsiloxane and magnetic particles of different chemical natures, shapes, and sizes have been synthesized. A comparative analysis of their mechanical properties (elastic modulus, strength, and elongation at break) has been performed depending on the mutual orientation of the internal structure, formed by magnetic filler particles during the synthesis of the composite in a magnetic field, and the direction of the external mechanical force applied to stretch the samples. The anisotropy of mechanical properties is most pronounced in composites based on anisometric particles, needle-like and plate-like. The highest values of anisotropy coefficient of elastic modulus are observed in the composite containing plate-like iron microparticles; for this composite, the ratio of the elastic moduli in the directions parallel and perpendicular to the internal structure reaches a value of five. The use of magnetic filler and its orientation by means of magnetic field is an effective method for creating polymer composites with anisotropy of mechanical properties.