Influence of silicon carbide/carbon black on the mechanical properties and cure characteristics of SBR/BR blends

The styrene-butadiene/butadiene-rubber blend was filled with silicon carbide (SiC) and carbon black (CB) and the impact of them on the cure characteristics and mechanical properties of the blend was investigated. The results showed adding 12 phr SiC and 30 phr CB enhanced the tensile strength, toughness, 100 and 200% modulus by ∼50%, 32%, 82%, and 86%, respectively. The incorporation of 12 phr SiC resulted in a reduction of ∼25% of the compression set. The SiC accelerated the curing reaction by reducing the curing times, and the CB led to decrease in the scorch times. The composite consisting of 30 phr CB and 12 phr SiC exhibits promise as a good candidate (the most improved mechanical and physical properties and the fastest curing) for efficient tire tread manufacturing. Based on the scanning electron microscopy images with a magnification of 3.0 kx, the SiC amount of 12 phr (parts per hundred rubber) caused the filler particle to agglomerate. This issue reduced the filler performance – by decreasing the particle surface area per volume—resulting in weaker mechanical, compression, and rheological properties.