Magnetorheological Fluids Based on Star-Shaped and Linear Polydimethylsiloxanes

Abstract

Magnetorheological fluids are obtained on the basis of star-shaped and linear PDMS containing 70, 75, and 80 wt % of carbonyl iron microparticles. While pure PDMS polymers are Newtonian fluids, composites exhibit pseudoplasticity. The viscoelastic properties of the obtained magnetorheological fluids of different composition are studied in magnetic fields up to 1 T. The viscosity and storage modulus of the magnetorheological fluids in the maximum magnetic field reach ~0.19–0.65 MPa s and 0.4 MPa, respectively. The relative increase in the viscosity and storage modulus of the magnetorheological fluids based on the star-shaped PDMS with a magnetic filler concentration of 70 wt % in a magnetic field exceeds four orders of magnitude. In the magnetic field, the yield stress of the magnetic composites is as high as 70 kPa at a magnetic field strength of 1 T.