Vulcanization is the conversion of a high-molecular material from the plastic to the elastic state. One of the key chemical reactions in this process is that of rubber with sulfur. Sulfur vulcanization, widely used in the rubber industry, requires the use of vulcanization accelerators such as Vulkacit®.

Vulcanization accelerators are not catalysts because they are part of the chemical reaction. The great variety of accelerators available is a result of their different influences on the vulcanization kinetics (scorch and cure time) and on physical properties such as tensile strength, elasticity or resistance to aging. In many cases, accelerators are combined to supply optimal processing and physical properties.

Key Properties

Mercapto accelerators
very fast accelerators giving a very broad plateau and good aging resistance.

Sulfenamide accelerators
fast but very safe accelerators providing a steep slope on the rheometer curve.

Thiuram accelerators
fast accelerators, especially for efficient or sulfurless cure.

Dithiocarbamate accelerators
very fast accelerators used alone or as a booster for thiazole and sulfenamide cure systems.

Amine accelerators
special accelerators for extraordinary applications.