Rubber compounding with two or more components has been extensively employed to improve various properties. In particular, natural rubber (NR)/ethylene-propylene-diene monomer rubber (EPDM) blends have found use in tire and automotive parts. Diverse fillers have been applied to NR/EPDM blends to enhance their mechanical properties. In this study, a new class of mineral filler, phlogopite, was incorporated into an NR/EPDM blend to examine the mechanical, curing, elastic, and morphological properties of the resulting material. The combination of aminoethylaminopropyltrimethoxysilane (AEAPS) and stearic acid (SA) compatibilized the NR/EPDM/phlogopite composite, further improving various properties. The enhanced properties were compared with those of NR/EPDM/fillers composed of silica or carbon black (CB). Compared with the NR/EPDM/silica composite, the incompatibilized NR/EPDM/phlogopite composite without AEAPS exhibited poorer properties, but NR/EPDM/phlogopite compatibilized by AEAPS and SA showed improved properties. Most properties of the compatibilized NR/EPDM/phlogopite composite were similar to those of the NR/EPDM/CB composite, except for the lower abrasion resistance. The NR/EPDM/phlogopite/AEAPS rubber composite may potentially be used in various applications by replacing expensive fillers, such as CB.

Natural rubber (NR) presents a number of advantages over other types of rubber but has poor resistance to chemicals and aging. The incorporation of ethylene propylene diene monomer (EPDM) into the NR matrix may be able to address this issue. Mineral fillers, such as carbon black (CB) and silica are routinely incorporated into various elastomers owing to their low cost, enhanced processability, good functionality, and high resistance to chemicals and aging. Other fillers have been examined as potential alternatives to CB and silica. In this study, phlogopite was surface-modified using 10 phr of compatibilizers, such as aminopropyltriethoxysilane (A1S), aminoethylaminopropyltrimethoxysilane (A2S), or 3-glycidoxypropyltrimethoxysilane (ES), and mixed with NR/EPDM blends. The effects of untreated and surface-treated phlogopite on the mechanical properties of the rubber blend were then compared with those of common fillers (CB and silica) for rubbers. The incorporation of surface-modified phlogopite into NR/EPDM considerably enhanced various properties. The functionalization of the phlogopite surface using silane-based matters (amino- and epoxide-functionalized) led to excellent compatibility between the rubber matrix and phlogopite, thereby improving diverse properties of the elastomeric composites, with effects analogous to those of CB. The tensile strength and elongation at break of the phlogopite-embedded NR/EPDM composite were lower than those of the CB-incorporated NR/EPDM composite by 30% and 10%, respectively. Among the prepared samples, the ES-functionalized phlogopite showed the best compatibility with the rubber matrix, exhibiting a tensile strength and modulus of composites that were 35% and 18% higher, respectively, compared with those of the untreated phlogopite-incorporated NR/EPDM composite. The ES-functionalized phlogopite/NR/EPDM showed similar strength and higher modulus (by 18%) to the CB/NR/EPDM rubber composite, despite slightly lower elongation at break and toughness. The results of rebound resilience and compression set tests indicated that the elasticity of the surface-modified phlogopite/NR/EPDM rubber composite was higher than that of the silica- and CB-reinforced composites. These improvements could be attributed to enhancements in the physical and chemical interactions among the rubber matrix, stearic acid, and functionalized (compatibilized) phlogopite. Therefore, the functionalized phlogopite can be utilized in a wide range of applications for rubber compounding.

To improve mechanical and magnetorheological properties of magnetorheological elastomers (MREs), a facile method was used to fabricate high-performance MREs which consisted of the core–shell complex microparticles with an organic-inorganic network structure dispersed in an ethylene propylene diene rubber. In this work, the proposed magnetic complex microparticles were in situ formed during MREs fabrication as a result of strong interaction between matrix and CIPs using carbon black as a connecting point. The morphology of both isotropic (i-MREs) and anisotropic MREs (a-MREs) was observed by scanning electron microscope (SEM). The effects of carbonyl iron particle (CIP) volume content on mechanical properties and hysteresis loss of MREs were investigated. The effects of CIP volume content on the shear storage modulus, MR effect and loss tangent were studied using a modified dynamic mechanical analyzer under applied magnetic field strengths. The results showed that the orientation effect became more pronounced with increasing CIPs in the a-MREs, whereas CIPs distributed uniformly in the i-MREs. The tensile strength, tear strength and elongation at break decreased with increasing CIP content up to 40 vol.%, while the hardness increased. It is worth noting that the tensile strength of i-MREs and a-MREs containing 40 vol.% CIPs still had high mechanical properties as a result of good compatibility between complex microparticles and rubber matrix. The MR performance of shear storage modulus and damping properties of MREs increased remarkably with CIP content due to strong dipole–dipole interaction of complex microparticles. Besides, the hysteresis loss increased with increasing CIP content as a result of magnetic field induced interfacial sliding between complex microparticles.

Magneto‐rheological elastomer (MRE) is a kind of smart material based on elastomer matrix and it is divided into isotropic (i‐MRE) and anisotropic MRE (a‐MRE) depending on the magnetic particle arrangement. In the i‐MRE, carbonyl iron particles (CIP) are randomly dispersed, while they form a chain‐like structure in the a‐MRE. Two manufacturing procedures of a‐MRE have been introduced. The a‐MRE‐1 was manufactured by one‐step process involving application of magnetic field and curing of matrix simultaneously. On the other hand, a‐MRE‐2 was manufactured by two‐step process in which the magnetic field was applied to induce CIP orientation and then the matrix was cured. The microstructure and mechanical properties of MRE were characterised by scanning electron microscope, universal testing machine and dynamic mechanical analysis. The results showed that the CIP content in MRE had no effect on the cure properties. A chain‐like structure existed in a‐MRE‐1, whereas the orientation structure of CIP in the a‐MRE‐2 was not as clear as that in a‐MRE‐1. The tensile strength of a‐MRE‐1 was the lowest because no interfacial reaction occurred between the CIP and the rubber molecules chain, whereas i‐MRE had the highest tensile strength.