his whole lorge Sweat to work Out Achilles his armour" Sir Thomas brow^ Michael M. Coleman receiued his B.Sc. in chemical technology at Borough Polytechnic, London, En. gland, in 1968 and his M.S. and Ph.D. in macromolecular science from Case Western Reserue lJniversit2 in 1971 and 1973, respectivi mer Chemicals Departmenl ny as a research chemist ii to obtaining his undergradL an analytical chemist for nine years in Zambia and England Dr Coleman has seueral Dublications in the fiela on the ay.

Raman and ESR spectroscopy has been used to study the thermal decomposition of accelerator systems based on derivatives of dimethyldithiocarbamic acid. The combination of these two spectroscopic techniques has proved to be a very powerful method for detecting intermediate compounds that are important for the elucidation of the mechanism of accelerated sulfur vulcanization.

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From studies of a series of accelerated sulfur vulcanizations of natural rubber, the structural basis of the reversion in macroscopic physical-mechanical properties has been determined. The amount of chemically induced trans-methine butadiene-like structure increases as the reversion process proceeds. When there is no observable reversion, there is no detectable trans-methine butadiene-like structure. The presence of the trans-methine butadiene-like structure is detrimental to the properties of the natural rubber vulcanizate. The vulcanization process involves two competing processes, namely, crosslinking and desulfuration. The latter process produces the trans-methine structure which is responsible for the reversion in properties.

A mechanism for the formation of the rubber-bound intermediate in the vulcanization of elastomers has been proposed. The active sulfurating agent is a polysulfide. Laser Raman spectroscopy has been used to provide significant evidence for this mechanism in the presence of cis-1,4-poly(butadiene).