Influence Of Silane Coupling Agent KH560 On Dynamic Mechanical Properties Of Magnetorheological Elastomers

Magnetorheological elastomers (MREs) are a new type of intelligent materials made by soft magnetic particles filled in a rubber matrix, whose stiffness could be controlled by an external magnetic field. Thus magnetorheological elastomers are widely applied in vibration and noise controls.Partilces and additives are important to mechanical properties of the magnetorheological elastomers. So this paper was based on the two factors to investigate the magnetorheological effect and loss factor of the MREs. And their dynamic shear properties under the magnetic field from 0 mT to 500 mT were measured by DHVTC vibration system.Two types of magnetorheological elastomers were prepared with two-component silicone rubber (RTV), pure ferrite partilces and silane coupling agent KH560. The influence of the KH560 on tensile property, magnetorheological effect and zero magnetic loss factor of the MREs were discussed. And it is found that, compared with the MRE without coupling agent, the tensile strength and the magnetorheological effect of MRE with the KH560 increased by 118.3% and 51.5% respectively, but the loss factor decreased by 23%. There are abvious holes between the particles and the rbber in the MRE without coupling agent. Stress concentration, magnetic energy loss and interfacial slip would be strengthened because of the holes. However, the KH560 would improve the surfacial compatibility between the particles and the rubber, and thus the holes were disappeared. As a result, the higher tensile strength and magnetorheological effect and the lower loss factor were achieved.Fe-Cr-Mo alloy particles, prepared by an electric charge machine, were filled in the RTV to prepare MREs. Magnetorheological effect and loss factor of the samples were also calculated respectively. The results showed that magnetorheological effect, zero magnetic modulus and loss factor of the 40% particles content MRE were 25%, 60KPa and 0.196, respectively. When the particles concentration increased to 70%, and the parameters mentioned above reached to 99%,130KPa and 0.236 respectively. Filler reinforcement effect, magnetic dipole effect and interfacial slip would be strengthened with the particles content varied from 40% to 70%, which result in the increasing of the parameters.In addition, it is still found that a higher magnetic field also causes a larger loss factor. The loss factor of the sample with 70% particles increases by 15.3% due to the enhancing magnetic field from OmT to 500 mT. It is due to the higher field-induced interaction among the particles.