Fabrication and properties of magnetorheological elastomers based on CR/ENR self-crosslinking blends

Magnetorheological elastomers (MREs) are intelligent materials, which are widely used as dampers to eliminate vibration. In this study, a new kind of MREs was designed using carbonyl iron particles (CIPs), carbon black (CB) and self-crosslinking blends, which were fabricated by reacting polychloroprene rubber with epoxidized natural rubber (CR/ENR blends). The interaction mechanism among CIPs, CB and a matrix in the fabrication process was discussed in detail. The morphology of isotropic MREs (i-MREs) and anisotropic MREs (a-MREs) was observed by scanning electron microscopy (SEM). The effect of CIP volume content on the mechanical properties of MREs was investigated. The effect of CIP volume content on the shear storage modulus, MR effect and loss factor was studied using a modified dynamic mechanical analyzer (DMA). The results revealed that the chain-like distribution of CIPs became more pronounced with increasing CIP content in a-MREs, whereas CIPs distributed uniformly in i-MREs. CIPs and CB bonded well with the rubber matrix as a result of their surface attraction effect to CR and ENR molecular chains. Therefore, MREs had excellent mechanical properties. The promoting effect of CB and CIPs on the self-crosslinking reaction was verified by crosslink density assessment. The shear storage modulus of MREs increased with the increase of CIP content, and the MR effect of i-MREs remarkably increased, while a-MREs decreased due to the obvious increase in initial storage modulus with increasing CIP content. The loss factor of MREs decreased obviously with the increase of CIP content.