Thiuram-accelerated sulfur vulcanization. I. The formation of the active sulfurating agent

✍ Scribed by M. Geyser; W. J. McGill

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 426 KB
• Volume: 60
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19960418)60:3<425::aid-app16>3.0.co;2-1

✦ Synopsis

Mixtures of tetramethylthiuram disulfide (TMTD)/ZnO and TMTD/sulfur/ZnO were heated in a DSC to various temperatures. Zinc dimethyldithiocarbamate (Zn,(dmtc)J formed only in undried TMTD/ZnO mixes, the reaction being catalyzed by water on the ZnO surface. The presence of ZnO delays the decomposition of TMTD by adsorbing thiuram sulfenyl radicals, which are needed to initiate tetramethylthiuram monosulfide (TMTM) and tetramethylthiuram polysulfide (TMTP) formation. Increased amounts of T M T M are formed in mixes where ZnO is present, and T M T P are detected prior to TMTM formation. ZnJdmtc), does not react with sulfur under conditions where labile hydrogen atoms are not available.