Sulfur Vulcanization of Simple Model Olefins, Part I: Characterization of Vulcanization Products of 2,3-Dimethyl-2-Butene

TLDR: In this paper, the mechanism of the sulfur vulcanization of rubber, 2,3-dimethyl-2-butene (C 612 ) was used as a simple, low-molecular-weight model alkene.

Abstract: To study the mechanism of the sulfur vulcanization of rubber, 2,3-dimethyl-2-butene (C 612 ) was used as a simple, low-molecular-weight model alkene. Only equivalent allylic positions are present in this alkene. Treating C 6 H 12 with a mixture of Zn, S 8 , and the accelerator tetramethylthiuramdisulfide at 140°C yields a mixture of addition products (C 6 H 11 -S n -C 6 H 11 ). RP-HPLC in combination with MS and H-NMR shows that the products differ only in the length of the sulfur bridge. Small quantities of isomerized products have been found, in which a 1,3-shift of the double bonf has occured