Enhancement of Particle Alignment Using Silicone Oil Plasticizer and Its Effects on the Field-Dependent Properties of Magnetorheological Elastomers

Abstract

The existing mold concept of fabricating magnetorheological elastomer (MRE) tends to encounter several flux issues due to magnetic flux losses inside the chamber. Therefore, this paper presents a new approach for enhancing particle alignment through MRE fabrication as a means to provide better rheological properties. A closed-loop mold, which is essentially a fully guided magnetic field inside the chamber, was designed in order to strengthen the magnetic flux during the curing process with the help of silicone oil (SO) plasticizers. The oil serves the purpose of softening the matrix. Scanning electron microscopy (SEM) was used to observe the surface morphology of the fabricated MRE samples. The field-dependent dynamic properties of the MREs were measured several ways using a rheometer, namely, strain sweep, frequency sweep, and magnetic field sweep. The analysis implied that the effectiveness of the MRE was associated with the use of the SO, and the closed-loop mold helped enhance the absolute modulus up to 0.8 MPa. The relative magnetorheological (MR) effects exhibited high values up to 646%. The high modulus properties offered by the MRE with SO are believed to be potentially useful in industry applications, particularly as vibration absorbers, which require a high range of stiffness.

Magnetorheological Elastomers: Fabrication, Characteristics, and Applications

“…Researches have been conducted to enhance the mechanical and MR characteristics of MREs by adding non-magnetic fillers as additives to MREs. Different types of non-magnetic fillers include reinforcing agents [ 92 , 93 , 94 , 95 ], plasticizers [ 96 , 97 , 98 ], and crosslink agents [ 99 , 100 ] that are related to the mechanical characteristics of MREs, in addition to the important magnetic fillers to increase MR properties. Mechanical reinforcing agents include carbon nanotube (CNT) [ 92 ], graphene [ 93 ], graphite [ 94 ], and carbon black [ 95 ].…”

Magnetorheological Effect of Magnetoactive Elastomer with a Permalloy Filler

“…The macroscopic properties of MAE and their dependence on external magnetic field are determined by the disposition of particles in the host polymer, structures formed by them, structural transformations occurring under the influence of the field, and large-scale deformations suffered by the material. The size of the particles together with their shapes and concentration, the overall formula of the composite including the nature of the matrix polymer predetermining the stiffness of the filled elastomer [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 ], and the external magnetic and mechanical influence vectors [ 32 ] are also important factors lying behind the specifics of the field-sensitivity.…”

“…The employment of spherical micro-sized carbonyl iron powders (CIPs), prepared by chemical decomposition of purified iron pentacarbonyl, is dictated by the good magnetic features demonstrated by this metal powder. Field-induced formation of CIP particle structures inside the matrix promote an increased MR effect [ 1 , 23 , 24 , 25 , 26 , 27 , 31 , 32 , 38 ].…”

“…Multiple experiments performed on MRE have resulted in a significant collection of research data pointing to a strong relationship between the rheological characteristics of the material and magnetic field. Partly, the results were obtained from studies on damping devices [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ] or from investigations dedicated to the magnetorheological effect [ 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 ]. For instance, influenced by a field of 0.8 T, a silicone and carbonyl iron-based sample initially polymerized in a field of 1.5 T demonstrated an increase of its shear modulus (G′) from 0.25 to 2.5 MPa [ 1 ].…”

“…An absolute and relative MR effect of 2 MPa and 284%, respectively, exhibited by the material at 290 mT, are described in [ 37 ]. At the same time, the authors of [ 38 ] also investigated the influence of the interior orientation of the composite on its performance. Whereas the maximal absolute effect shown by an isotropic and anisotropic sample in a field of 0.8 T was 0.3 and 0.8 MPa, respectively, the relative MR effect amounted to 646 and 343%, respectively.…”