Influence of TiO2 on mechanical, microstructural, and electrical properties of TiO2/rubber composites

In recent years, materials with high dielectric constant and tensile strength are highly sought after in various electronic applications and industries. Ceramic materials have some of the highest dielectric constant values but their applications are limited by their mechanical properties. On the other hand, elastomer exhibit high and beneficial mechanical properties but have low dielectric constant values. Hence, by producing composite from these two materials the limitations of each individual material will be solved. TiO2 was chosen as filler to different types of rubber matrix, STR, ENR 25 and ENR 50, in this research due to its potential of high dielectric constant value and low cost. Tensile strength test on the STR composites with different TiO2 loadings, 0, 5, 10, 20, 30 and 50 phr, show increase of stress at any point after 500% of strain from 1 MPa to 3 MPa but composite with 50 phr recorded lower values than composite with 30 phr due to the loading stress within the composite with 50 phr that affects the efficiency of network chains of rubber to orient themselves in the direction of stretching. ENR 25 and ENR 50 with 20 phr recorded 4.0 MPa and 4.1 MPa respectively which are significantly higher than STR at 500% of strain. Aaprt from that, the composites were also subjected to LCR test. At any point between 75 kHz to 30 MHz, the dielectric constant of the STR composites with different loadings increases as the filler loading increases within range of 2.9 to 3.4 dielectric constant at 10 MHz. In comparison between STR and ENR composites at 20 phr, ENR composites have significantly higher dielectric constant than STR composite where ENR 50 recorded the highest at 7.4.