Influence of pyrolytic carbon black and pyrolytic oil made from used tires on the curing and (dynamic) mechanical properties of natural rubber (NR)/styrene-butadiene rubber (SBR) blends

Pyrolytic carbon black (CBp) and pyrolytic oil (Op) made from used tires were used in natural rubber (NR)/ styrene-butadiene rubber (SBR) blends.The effects of CBp and Op on the processing properties, the mechanical properties and the dynamic mechanical properties of the NR/SBR blends were investigated and compared with a control sample that was prepared with N550 and commercial process oil.It was found that the effect of CBp on the processing properties of the NR/SBR blends was similar to that of N550.With the increase of the CBp content, the curing properties of the NR/SBR blends changed little.The reinforcing effect of CBp was inferior to that of N550.With the increase of the CBp content, the tensile strength, tear strength and modulus at 100% elongation of the NR/SBR vulcanizates decreased significantly.Dynamic mechanical properties of the NR/SBR blends were also affected and all samples comprising CBp have a higher tan !than control sample.It is suggested that the low surface area and high ash content of CBp strongly effects all of these property changes of the NR/SBR blends.The morphology and distribution of the carbon black particles are studied using a scanning electron microscope.It was also found that with the increase of the Op content, the properties of the NR/SBR blends were strongly affected due to the high sulfur content of Op, which produced a high crosslinking density.