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Benzothiazole‐accelerated sulfur vulcanization. III. 2‐Bisbenzothiazole‐2,2′‐disulfide as accelerator for 2,3‐dimethyl‐2‐butene
Author(s) -
Morgan B.,
McGill W. J.
Publication year - 2000
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(20000531)76:9<1395::aid-app4>3.0.co;2-8
Subject(s) - vulcanization , benzothiazole , disproportionation , sulfur , polymer chemistry , chemistry , disulfide bond , thiol , organic chemistry , catalysis , natural rubber , biochemistry
2‐Bisbenzothiazole‐2,2′‐disulfide (MBTS)‐accelerated sulfur vulcanization, in the absence of ZnO, 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 the residual curatives, intermediates, and products were analyzed by HPLC at various stages of the reaction. The formation of accelerator‐terminated polysulfidic pendent groups is accompanied by the liberation of 2‐mercaptobenzothiazole (MBT) and more MBT is liberated on crosslinking. Bis(alkenyl)‐crosslinked products with varying degrees of sulfuration result. It was shown that crosslinking by a reaction between pendent groups and the model compound, and by disproportionation of pendent groups, leads to limited crosslinking. H 2 S was not evolved during crosslinking. 2,3‐Dimethyl‐2‐butene–benzothiazole disulfide (TME–S 2 Bt) and 2,3‐dimethyl‐2‐butene–1‐thiol (TME–SH) were synthesized and it was shown that rapid crosslinking occurs between TME–S x Bt and TME–S x H (where x > 1), the reaction liberating MBT. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1395–1404, 2000