ABSTRACT
The ability to synthesize addition polymers of predetermined molecular weights and of narrow polydispersity was virtually created by the development of the anionic living polymer technique by Szwarc' in the late 1950s. There are three main types of anionic initiators: organometallic compounds — especially alkyl lithiums — alkali metals, and electron transfer catalysts. The dithiocarboxylate group may be introduced onto the polymer ends by reaction of living polymer with carbon disulfide. Terminal hydroxyl groups may be introduced by using an initiator with an appropriately masked hydroxyl group. Vicinal organic dihalides of whatever structure do not readily react additively with living vinyl polymers and, therefore, are unsuited for preparing halogen terminated material. Propagating species is capable of propagation at both ends of the chain to yield telechelic living polymers. The ability to achieve living polymerizations allows for telomer formation by introducing reactive terminal groups through the use of a termination reaction of choice.
