Properties of SBR/NR Blend: The Effects of Carbon Black/Silica (CB/Si) Hybrid Filler and Silane Coupling Agent

Abstract

In the current research, investigation of natural rubber (NR)/styrene butadiene rubber (SBR) reinforced with carbon black (CB)/silica (Si) and with and without silane coupling agent (Si69) was analyzed. The total hybrid filler (CB/Si) concentration in the composite was fixed at 50 phr. Cure characteristics, mechanical properties and surface morphology were examined. The addition of a silane coupling agent improves the mechanical properties of NR/SBR rubber composites reinforced with CB/Si hybrid fillers. Compared with NR/SBR composites with Si69, addition of 0/50 CB/Si resulted in 53% decrease of tensile strength and 81% increase of elongation at break, superior to that of NR/SBR composites without Si69. When Si69 was used as a binding agent, the scanning electron micrograph (SEM) of the tensile fractured surface clearly shows the better dispersion of hybrid fillers in the NR/SBR matrix.