Magnetic polyurethane elastomers with wide range modulation of elasticity

A new magnetorheological elastomer that demonstrates drastic and reversible changes in dynamic modulus in air was obtained. The magnetic elastomer consists of polyurethane and carbonyl iron particles. The magnetic elastomer with a volume fraction of 0.29 exhibited a reversible increase by factors of 277 of the storage modulus and 96 of the loss modulus upon a magnetic field of 500 mT. The elastomer underwent high mechanical toughness with a braking strain exceeding 0.8, and demonstrates the giant magnetorheological behavior for half a year after the synthesis without degradation.