Structural characterization of vulcanizates. Part VII. The N-cyclohexylbenzothiazole-2-sulfenamide-accelerated natural rubber–sulfur system
Article first published online: 9 MAR 2003
Copyright © 1967 John Wiley & Sons, Inc.
Journal of Applied Polymer Science
Volume 11, Issue 11, pages 2255–2269, November 1967
How to Cite
Porter, M. (1967), Structural characterization of vulcanizates. Part VII. The N-cyclohexylbenzothiazole-2-sulfenamide-accelerated natural rubber–sulfur system. J. Appl. Polym. Sci., 11: 2255–2269. doi: 10.1002/app.1967.070111113
- Issue published online: 9 MAR 2003
- Article first published online: 9 MAR 2003
- Manuscript Received: 11 APR 1967
The crosslinking efficiency of sulfur in the vulcanization system comprising (in parts by weight) natural rubber (100), sulfur (1.5), N-cyclohexylbenzothiazole-2-sulfenamide (2.37), zinc oxide (5), and lauric acid (1–10) is relatively insensitive to the lauric acid concentration and to the temperature of vulcanization (between 100 and 140°C.). The networks formed contain initially 8–11 combined sulfur atoms per chemical crosslink present, but this number falls progressively to about 4 as the reaction proceeds. The results are consistent with the intermediate formation of a rubber-soluble complex of cyclohexylamine with zinc benzothiazolyl mercaptide. This complex is believed to be responsible also for the further slow crosslinking which the vulcanizates undergo on standing at room temperature.