The biological and chemical desulfurization of crumb rubber for the rubber compounding

The disposal of used car tires has become a major environmental problem, especially in densely populated countries that use motor vehicles as the principle means of transportation. Widespread recycling of waste tires has not taken place because it has not proven to be cost effective. Although there are obvious environmental reasons for recycling waste tires, to date it has not proven to be economically valuable. The aim of this study is to find a more economical way of recycling used car tires. This was done by the “unvulcanization” of vulcanized crumb rubber by two different treatments; chemical treatment with di-(cobenzanidophenyl)disulfide, and microbial treatment with T. peromatabolis. The experimental results indicate that the processing of crumb rubber, as well as the end-product properties, were enhanced by both these treatments, with the microbial treatment being the most effective. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 72: 1543–1549, 1999