'Re-thinking' sulfur curing, part 1
Since Charles Goodyear discovered the sulfur curing of NR in 1839, many studies have been carried out to understand its mechanism. Nowadays, the broadly accepted mechanism includes an activated accelerator Zn-complex which enables sulfur coupling to the polymer in the allylic position to the double bond. Modern passenger car tire treads no longer contain natural rubber but a blend of SSBR and BR, filled with a silica /silane system. Is it possible to transfer all NR-gained knowledge to such a modern passenger car tire tread formulation or is re-thinking sulfur curing required?