“Re-think” Sulfur Curing

Since Charles Goodyear discovered the sulfur curing of Natural Rubber in 1839, many studies were carried out to understand the mechanism of sulfur curing. Nowadays, the broadly accepted mechanism includes an activated accelerator complex formed by Zinc oxide, stearic acid, accelerators and sulfur. Furthermore, it is also broadly accepted that the coupling of the sulfur to the polymer takes place in the allylic position to the double bond. Modern passenger car tire treads do not contain any longer Natural Rubber but a blend of SSBR and BR, filled with a silica /silane system. Is it possible to transfer all gained knowledge from the Natural Rubber crosslink reaction to such a modern passenger car tire tread formulation or is it required to “re-think” the sulfur curing?