𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Sulfur vulcanization of polyisoprene accelerated by benzothiazole derivatives. III. The reaction of 2-bisbenzothiazole-2,2′-disulfide with sulfur and ZnO in polyisoprene

✍ Scribed by M. H. S. Gradwell; W. J. Mcgill


Publisher
John Wiley and Sons
Year
1996
Tongue
English
Weight
526 KB
Volume
61
Category
Article
ISSN
0021-8995

No coin nor oath required. For personal study only.

✦ Synopsis


The sulfur vulcanization of polyisoprene accelerated by 2-bisbenzothiazole-2,2'-disulfide (MBTS) was investigated. Rubber compounds were heated in a DSC and removed at various temperatures along the DSC thermal curve. The rubber vulcanizate was analyzed for crosslink density and for residual reactants and extractable reaction products. MBTS reacts readily with sulfur, and the polysulfidic accelerator complexes react with the rubber chain to form pendent groups. Crosslinking results from hydrogen abstraction, by the benzothiazole pendent group, from a neighboring chain. 2-Mercaptobenzothiazole, a product of crosslinking, also acts as an accelerator in the later stages of the reaction. MBTS has been shown not to react with ZnO and the higher crosslink densities obtained when ZnO is present are attributed to ZnO aiding the abstraction of the benzothiazole pendent group to give zinc mercaptobenzothiazole. A mechanism for the MBTS acceleration of sulfur vulcanization is proposed.


📜 SIMILAR VOLUMES


Effect of carboxylic acids on 2-bisbenzo
✍ W. J. McGill; S. R. Shelver 📂 Article 📅 1999 🏛 John Wiley and Sons 🌐 English ⚖ 219 KB 👁 2 views

The effect of benzoic and stearic acids on 2-bisbenzothiazole-2,2Ј-disulfide (MBTS)-and tetramethylthiuram disulfide (TMTD)-accelerated sulfur vulcanization of polyisoprene compounds, containing ZnO, was studied at 150°C. In the presence of ZnO, the acids are rapidly converted to their zinc salts th

Sulfur vulcanization of polyisoprene acc
✍ M. H. S. Gradwell; W. J. Mcgill 📂 Article 📅 1995 🏛 John Wiley and Sons 🌐 English ⚖ 555 KB

Polyisoprene compounds with sulfur and with sulfur and 2-mercaptobenzothiazole (MBT) were vulcanized by heating in a differential scanning calorimeter (DSC) a t a programmed rate. The reaction was stopped a t various temperatures along the thermogram and the product analyzed by determining the cross

Effect of carboxylic acids on 2-bisbenzo
✍ W. J. McGill; S. R. Shelver 📂 Article 📅 1999 🏛 John Wiley and Sons 🌐 English ⚖ 180 KB 👁 2 views

Polyisoprene was vulcanized by 2-bisbenzothiazole-2,2Ј-disulfide (MBTS)/ sulfur and tetramethylthiuram disulfide (TMTD)/sulfur in the absence and presence of benzoic and stearic acids. It was found that the crosslink density of MBTS vulcanizates is halved by the addition of carboxylic acids and this

Sulfur vulcanization of polyisoprene acc
✍ M. H. S. Gradwell; W. J. McGill 📂 Article 📅 1996 🏛 John Wiley and Sons 🌐 English ⚖ 703 KB

Polyisoprene was vulcanized with N-cyclohexylbenzothiazole sulfenamide (CBS), sulfur, and zinc oxide by heating in a Differential Scanning Calorimeter (DSC) at a programmed rate to given temperatures. The reaction was quenched and the product analyzed. Soluble curatives and reaction intermediates we

Tetramethylthiuram disulfide and 2-merca
✍ B. V. K. M. Giuliani; W. J. McGill 📂 Article 📅 1996 🏛 John Wiley and Sons 🌐 English ⚖ 608 KB

Polyisoprene was vulcanized with the binary accelerator system tetramethylthiuram disulfide-2-mercaptobenzothiazole (TMTD-MBT) in the absence of ZnO. Samples were heated in a DSC at a programmed rate, the reaction was stopped a t points along the thermal curve, and the system was analyzed. Extractab