Synthesis of Silicone Elastomers Containing Silyl-Based Polymer-Grafted Carbonyl Iron Particles: An Efficient Way To Improve Magnetorheological, Damping, and Sensing Performances

Abstract

The synthesis and characterization of isotropic magnetorheological elastomer (MRE) with significantly enhanced utility properties is presented. Common drawbacks of classical MREs, such as poor particle wettability, dispersibility, low thermooxidative stability, low chemical stability, and insufficient durability, were eliminated by grafting the carbonyl iron (CI) particles with poly(trimethylsilyloxyethyl methacrylate) (PHEMATMS) using surface-initiated atom transfer radical polymerization (ATRP). Two sets of the MREs were prepared containing bare CI and CI grafted with PHEMATMS chains (CI-g-PHEMATMS). The effects of the coating on magnetorheological behavior in oscillatory shear, as well as the sensing properties of the prepared MREs, were evaluated. The mechanical properties in tensile mode and the particle filler/polydimethylsiloxane (PDMS) matrix interactions were investigated using a dynamic mechanical analysis. The PHEMATMS grafts considerably improved the CI particles' mobility, probably by preventing a partial cross-linking with the PDMS matrix. Besides the plasticizing effect, the MRE containing CI-g-PHEMATMS exhibited moderate mechanical performance and a slightly improved relative magnetorheological effect, but significantly enhanced damping factor, improved magnetostriction, and provided good sensing capability, which make such material highly promising for intended practical applications.

Effect of Structure of Polymers Grafted from Graphene Oxide on the Compatibility of Particles with a Silicone-Based Environment and the Stimuli-Responsive Capabilities of Their Composites

“…Due to these facts the heat redistribution in the sample is more complicated and transformation from light to mechanical energy needs more time. As was also investigated by our group, the short polymer chains act as plasticizers, and even if they are grafted from the reinforcing surface like carbon nanotubes or carbonyl iron, the mechanical properties are lower [10,15,51]. In good agreement with the literature, all types of polymer chains grafted from GO provided a plasticizing effect, therefore the photo-actuation performance was better in comparison to the neat GO.…”

Magnetorheological Elastomers: Fabrication, Characteristics, and Applications

“…Martin et al [ 62 ] reported the characteristics of MREs by coating poly(trimethylsilyloxyethyl methacrylate) (PHEMATMS) on the surface of CI particles, in which the CI-g-PHEMATMS particles showed about 6.2% reduction in magnetization than neat CI particles due to the 10–20 nm coating thickness. However, it was possible to improve thermo-oxidation stability and anti-acid/corrosion properties through polymer coating.…”

Smart Non-Woven Fiber Mats with Light-Induced Sensing Capability

“…Since, the intended application of the prepared fiber mats is the photo-actuation, which is the dynamic process of reversible actuation upon certain force and frequency, the DMA investigations have been performed. Moreover, the position of the glass transition can also provide additional information about polymer chain mobility as we published previously [5]. Storage modulus represents reversible energy given by material upon dynamic mechanical stimulation, which is an important factor for elucidation of the mechanical performance.…”

“…Smart systems belong to the group of materials capable of changing the basic properties, when they are exposed to external stimuli such as electric [1][2][3], magnetic [4,5], thermal [6,7], pH [8,9], or light [10,11]. In case of light stimulation, such smart systems can exhibit the shape [12] or resistivity [13] change or generate electric output [14].…”