Synergistic effect of carbon black and carbon-silica dual phase filler in natural rubber matrix

In this article, the synergistic effects of carbon black (CB) and modified carbon-silica dual phase filler (MCSDPF) on the properties of natural rubber (NR) were investigated. MCSDPF was prepared by modifying carbon-silica dual phase filler (CSDPF) with bis(3-triethoxysilylpropyl)tetrasulphane (Si-69). Fourier transform infrared spectroscopy and thermogravimetric analyzer analyses revealed that Si-69 was successfully grafted to CSDPF. NR-based compounds containing various combinations of MCSDPF and CB were prepared through a mechanical mixing. Investigations of mechanical properties, ageing resistance, abrasion resistance, dynamic mechanical properties, and morphology of tear fractured surface of MCSDPF/CB/NR vulcanizates were conducted. Our study shows that adding MCSDPF led to significant improvement in the tear resistance, fatigue life, and elongation at break of MCSDPF/CB/NR vulcanizates. Optimum stoichiometric combination of MCSDPF and CB inside the NR matrix was derived (ratio of MCSDPF and CB in wt%=15/50), which showed synergistic effects of MCSDPF upon CB that was ultimately reflected in their tensile strength, wet skid resistance, and rolling resistance. POLYM. COMPOS., 35:1466-1472, 2014.