Vulcanization accelerator

A vulcanization accelerator is a chemical substance used in the rubber industry is used, so that the vulcanization of rubber faster or at lower temperatures occurs. A large number of groups of substances can serve as accelerators, the most important here being organic materials containing sulfur and nitrogen , in particular derivatives of benzothiazole .

Mode of action

During vulcanization, the accelerator converts the sulfur into a compound that reacts with rubber faster than the sulfur itself. Alternatively, the accelerator can first react with the rubber and transform it into a form that quickly combines with sulfur.

history

Already in the original patent for the vulcanization process, which was granted to Charles Goodyear in 1844 , compounds with alkali metals are mentioned as vulcanization accelerators. Magnesium oxide , zinc oxide, and basic lead carbonate were used until the early 20th century, before the benefits of the organic compound aniline were discovered. This was replaced a few years later by the less toxic thiocarbanilide and finally by mercaptobenzothiazole (MBT) around 1925 . Since then, compounds based on MBT have proven particularly useful in the vulcanization of synthetic rubbers .

Classification

Ultra Accelerator
dithiocarbamates , thiuram disulfides and monosulfides, xanthates

Semi-ultra-accelerator / semi-ultra-accelerator
Mercaptobenzothiazole and aldehyde amine condensation products

Moderately strong accelerators
dibenzothiazyl disulfide , DCBS , diarylguanidines such as diphenylguanidine , aryl biguanides such as o -tolyl biguanide , hexamethylenetetramine , aldehyde ammonia and most condensation products from aliphatic aldehydes and aromatic amines

Weak accelerators
triarylguanidines, diarylthioureas and the condensation products of formaldehyde and aromatic amines

literature

M. Bögemann: On the history and importance of organic vulcanization accelerators . In: Angewandte Chemie . tape 51 , no. 8 , February 26, 1938, p. 113–115 , doi : 10.1002 / anie.19380510802 .

Individual evidence

↑ ^a ^b ^c Accelerator. In: Encyclopædia Britannica . Retrieved June 19, 2019 .
↑ M. Bögemann: On the history and importance of organic vulcanization accelerators . In: Angewandte Chemie . tape 51 , no. 8 , February 26, 1938, p. 113–115 , doi : 10.1002 / anie.19380510802 .

[britannica-1] Accelerator. In: Encyclopædia Britannica . Retrieved June 19, 2019 .

[boegemann1938-2] M. Bögemann: On the history and importance of organic vulcanization accelerators . In: Angewandte Chemie . tape 51 , no. 8 , February 26, 1938, p. 113–115 , doi : 10.1002 / anie.19380510802 .