Anodic oxidation of sodium 2-mercaptobenztiazolate anion in the presence of 5-methyl-2-hexanol

The anodic oxidation of the sodium 2-mercaptobenztiazolate anion in alkaline solution yields a finely dispersed difficultly filterable form of di-(2-benztiazolyl)disulfide, an accelerant of the rubber sulfur vulcanization. A crucial problem in the establishing of the continuous di-(2-benztiazolyl)disulfide electrosynthesis is the choice of reaction mixture, which ensures easy filtration of the target product. It was found by using oscillographic voltammetry at platinum microelectrode that the sodium 2-mercaptobenztiazolate anion in aqueous alkaline solution in the presence of 5-methyl-2-hexanol is oxidized to a radical that undergoes dimerization, thus yielding easily filterable form of di-(2-benztiazolyl)disulfide. The obtained result is explained by assuming that the dimer formation occurs in the 5-methyl-2-hexanol adsorption layer at the electrode surface. A reaction scheme of the process is suggested.