Structural characterization of vulcanizates. Part VII. The N-cyclohexylbenzothiazole-2-sulfenamide-accelerated natural rubber–sulfur system

✍ Scribed by M. Porter

• Publisher: John Wiley and Sons
• Year: 1967
• Tongue: English
• Weight: 664 KB
• Volume: 11
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.1967.070111113

✦ Synopsis

T h e crosslinking efficiency of sulfur in the vulcanization system comprising (in parts by weight) natural rubber (loo), sulfur ( 1.5), N-cyclohexylbenzothiazole2b3ulfensmide

(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 14OOC.). 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 mercabtide. This complex is believed to be responsible also for the further slow crosslinking ivhich the vulcanizates undergo on standing at room temperature.