Electrical and mechanical characterization of vulcanized natural rubber filled with BaTiO3 ceramic filler

Ceramic rubber composites made of natural rubber (NR) loaded with various concentrations of barium titanate (BaTiO 3 ) particles were prepared by mixing and hot pressing. A silane coupling agent (KH-570) was utilized to modify the BaTiO 3 particles surface. The successful attachment of the coupling agent to the BaTiO 3 particles was confirmed by Fourier transforms infrared spectroscopy. The influence of surface modified BaTiO 3 (SMBT) particles concentration on the morphological, cure, mechanical, and electrical properties of the resulting samples was explored. The elongation at break and the tensile strength decreased with the addition of SMBT particles, while the hardness of composites increased. An enhancement of the dielectric constant ( ε′) of the composites was observed by incorporation of SMBT particles. The measured ε′ of the composites was modeled using the theories of a heterogeneous medium. The dielectric loss showed a clear peak at high frequency, indicating the relaxation process of the orientational polarization.