Synthetic rubber mercaptans

A large number of chemical devulcanization agents for natural and synthetic rubbers have been developed. These include phosphines and phosphates, numerous sulfides and mercaptans, metal salts such as methyl iodide, phenyl lithium, lithium aluminum hydride, and phase-transfer catalysts. ... 

Alkylation plays an important role in the production of synthetic rubber of the GR-S type, this unit process being employed for the preparation of ethylbenzene from which styrene is derived. Much lauryl mercaptan has been manufactured for use as a modifier in making synthetic rubber. 

Alkyl Bound to Miscellaneous Elements. Several compounds in which alkyl is bound to a sulfur atom have become quite important in recent years for example, the mercaptans, such as amyl and ethyl mercaptan, are used as warning agents in natural gas because of their intense and disagreeable odor. Mercaptans are also employed in organic syntheses as, for instance, the manufacture of sulfonal by the condensation of ethyl mercaptan (ethanethiol) with acetone, followed by oxidation. In recent years a very considerable amount of mercaptan has been used for controlling the polymerization reaction between butadiene and styrene to form synthetic rubber (GR-S). 

Precaution Combustible Uses Antiozonant in polyunsat. elastomers antioxidant, antiozonant for gasoline, mercaptans, synthetic rubber (NR, IR, BR, SBR) antioxidant/antiozonant in food-contact rubber articles for repeated use Regulatory FDA 21CFR 177.2600 Manuf./Distrib. ChemService http //WWW. chemservice. com] Crompton/Uniroyal... 

N,N -Dibutylthiourea is a nitrosamine free accelerator, antidegradant, and corrosion inhibitor. Ultra-accelerator for mercaptan-modified CR. It is slightly safer than DETU. It is also used as a secondary accelerator for NR and synthetic rubbers. It disperses easily in rubber. It is non-staining and does not bloom. It is practically odorless. Antioxidant for NR, antiozonant for NR and SR, particularly SBR. 

Some formulations lor sivrene-hutudiene rubber iGR-S) contain dndccyl mercaptan which plays Ihe role of a chain-transfer agent used to control the mnleculai weight of ihe linal synthetic product. 

Since polymerization at lower temperatiures results in a superior synthetic GR-S (cold rubber), the tertiary modifiers have an opportunity to play an important role in this process. The tertiary mercaptans are a mixture of mercaptans having 11-13 carbon atoms with an average molecular weight corresponding to about 12 carbon atoms, as compared to commercial lauiyl mercaptan which is 60 per cent normal lauiyl and the balance normal mercaptans having 10,14, and 16 carbon atoms. Tertiary... 

Isobutene is primarily used as a precursor for various chemicals. It is used in a polymerisation reaction with isoprene for the production of polybutene (butyl rubber used for the production of tires and other synthetic mbbers). Further products include polyisobutene, diisobutene, methacrolein, methacrylic acid, tert-butanol, alkyl-tert-butyl ether, additives for fuels and lubricants, vitamins, fragrances, isoprene, mercaptanes, alkylphenols, antioxidants in the food industry. 

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