Tert-dodecyl mercaptan, also known as TDM or tert-dodecanethiol, is a chemical compound with the formula C12H25SH. It is a branched-chain thiol primarily used as a chain transfer agent in the polymerization of various monomers, especially in the production of butadiene-styrene polymers like SB latex, SB rubber, and ABS. It's also used as an intermediate, a process regulator, and an additive in lubricants.