Polymers are usually non-magnetic in nature. The introduction of magnetic materials imparts magnetic properties to the polymer as well as improves the physical properties of polymer/rubber matrix. The merits of polymer bonded magnets (PBMs) over their metallic and ceramic counterparts comprise low weight, resistance to corrosion, ease of fabrication and capability for high production rates. In the present work nickel ferrite was prepared by coprecipitation method. The prepared ferrite fillers are embedded in natural rubber (NR) matrix by mechanical mixing at different loadings to get the rubber ferrite composites (RFCs) and their properties were studied as a function of filler loading from 0-75 phr. The mechanical property study reveals that tensile strength, elongation at break and modulus (100%) increases up to 25 phr of filler loading and afterwards it shows a marginal fall, but Shore hardness significantly increases with filler loading. The magnetic measurements were done on the filler and prepared RFCs. The results show that there is a significant improvement in the coercivity, magnetic retentivity and saturation magnetization and is linearly dependent on the filler amount. The solvent diffusion study shows that the equilibrium solvent uptake decreases with increase in filler content which is in accordance with mechanical and magnetic studies.
Ananthika V, Sreedha Sambhudevan, and Sanker, B., “Mechanical, Swelling and Magnetic property studies of Natural rubber-Nickel ferrite composites”, International Journal of Applied Engineering Research, vol. 10, 2015.