Electrical and Electrorheological Properties of Alumina/Natural Rubber (STR XL) Composites

• Main Authors: Anuvat Sirivat, Piraya Wongpinthong, Mean Longtong, Nuttapot Uttanawanit, Nuchnapa Tangboriboon, Ruksapong Kunanuruksapong
• Format: Article
• Language: English
• Published: MDPI AG 2010-01-01
• Series: Materials
• Subjects: natural rubber; dielectric elastomer; alumina
• Online Access: http://www.mdpi.com/1996-1944/3/1/656/

The electrorheological properties (ER) of natural rubber (XL)/alumina (Al2O3) composites were investigated in oscillatory shear mode under DC electrical field strengths between 0 to 2 kV/mm. SEM micrographs indicate a mean particle size of 9.873 ± 0.034 µm and particles that are moderately dispersed in the matrix. The XRD patterns indicate Al2O3 is of the β-phase polytype which possesses high ionic conductivity. The storage modulus (G′) of the composites, or the rigidity, increases by nearly two orders of magnitude, with variations in particle volume fraction and electrical field strength. The increase in the storage modulus is caused the ionic polarization of the alumina particles and the induced dipole moments set up in the natural rubber matrix.