Magnetorheological response of Permalloy@styrene-b-(ethylene-co-butylene)-b-styrene elastomersas a function of filler concentration

Abstract

Developing advanced magnetorheological elastomers (MREs) with a range of specific characteristics is essential for matching the growing demands from a wide spectrumof applications such as automotive, healthcare, sensors, and actuators. However, thecompatibility problems between constituents and the low magnetorheological(MR) effect have limited their performance and integration into actual applications.Here, a novel MRE consisting of styrene-b-(ethylene-co-butylene)-b-styrene (SEBS)and Ni-rich Permalloy (Ni80Fe17Mo3) has been developed with remarkable functionalproperties. The correlation between the filler concentration and microstructural,mechanical, thermal, magnetic, and MR properties is reported. The incorporation ofNi-rich Permalloy has a reinforcement effect in the polymer matrix and leads to animprovement of the thermal stability. Further, the saturation magnetization and rem-anence of the composites increase with increasing filler content. In particular, the sat-uration magnetization increases from 14.3 to 41.9 A m2/kg, and the remanence from1.2 to 4.0 A m2/kg when the concentration increases from 20 to 60 wt%. Finally, theMR effect of composites with 20, 40, and 60 wt% filler content is 8%, 15%, and 35%,respectively. A magnetic dipole interaction model is used to discuss the MR effectand a relation between the MR effect and the main parameters affecting it is pro-posed. Importantly, the obtained MR values are higher when compared with relatedcomposites for the same magnetic content, and for the same or similar polymericmatrices, demonstrating the suitability of the developed materials for the fabricationof high-response functional MR devices