2-Bisbenzothiazole-2,2Ј-disulfide (MBTS)-accelerated sulfur vulcanization in the presence of ZnO and bis(2-mercaptobenzothiazole)zinc(II) [Zn(mbt) 2 ] was studied using 2,3-dimethyl-2-butene (TME) as a model for polyisoprene. Reactions were carried out in sealed tubes at 150°C and residual curatives
Photodegradation of 2-mercaptobenzothiazole disulfide and related benzothiazoles
✍ Scribed by Zuzana Zajíčková; Cyril Párkányi
- Publisher
- Journal of Heterocyclic Chemistry
- Year
- 2008
- Tongue
- English
- Weight
- 300 KB
- Volume
- 45
- Category
- Article
- ISSN
- 0022-152X
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✦ Synopsis
Abstract
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The photodegradation of 2‐mercaptobenzothiazole disulfide, 2‐mercaptobenzothiazole and benzothia‐zole was investigated. Benzothiazole was found to undergo photodimerization into 2,2′‐bibenzothiazole, and in the presence of oxygen to give two additional photoproducts ‐ 2‐hydroxybenzothiazole and 2‐methylbenzothiazole. The major degradation products of 2‐mercaptobenzothiazole are benzothiazole and 2‐benzothiazolesulfonic acid, with 2,2′‐thiobisbenzothiazole and 2‐mercaptobenzothiazole disulfide as the minor degradation products. Direct photolysis of 2‐mercaptobenzothiazole disulfide gave 2‐mercapto‐benzothiazole and in acetonitrile 2‐thiocyanatobenzothiazole was also detected. A mechanism is proposed to rationalize the formation of photodegradation products.
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