D 2421 (OTTO) tert-Dodecylmercaptan, 97% Cas 25103-58-6 - used as a synthetic chemical. D 2421 (OTTO) tert-Dodecylmercaptan, 97% Cas 25103-58-6 - used primarily as a molecular weight regulator in polymerizations used, in particular for free-radical polymerizations of vinylic monomers such as of butadiene, styrene, carboxylated styrene, acrylic acid, acrylonitrile, acrylic esters, vinyl ethers or their mixtures, wherein particularly the emulsion in water.