Thiurams

Thiurams are ultra-fast accelerators and, because of the sulfur in their molecular structure, also work as sulfur donors. Used in small amounts as secondary accelerators, they speed up the primary system noticeably.

When used without elemental sulfur or with very little sulfur (EV systems), they build short, heat-stable crosslinks. This gives a vulcanizate with high heat ageing resistance.

Classic thiurams (TMTD, TETD, TBTD) can form nitrosamines because they derive from secondary amines. TBzTD and TiBTD are considered safe substitutes in this respect.

Comparison

Relative, qualitative comparison; varies with formulation and rubber type.