In polymer chemistry, chain transfer is a polymerization reaction by which the activity of a growing polymer chain is transferred to another molecule:[1][2]
where • is the active center, P is the initial polymer chain, X is the end group, and R is the substituent to which the active center is transferred.
Chain transfer reactions reduce the average molecular weight of the final polymer. Chain transfer can be either introduced deliberately into a polymerization (by use of a chain transfer agent) or it may be an unavoidable side-reaction with various components of the polymerization. Chain transfer reactions occur in most forms of addition polymerization including radical polymerization, ring-opening polymerization, coordination polymerization, and cationic polymerization, as well as anionic polymerization.
Chain transfer (in a chain polymerization): Chemical reaction occurring during a chain polymerization in which an active center is transferred from a growing macromolecule or oligomer molecule to another molecule or to another site on the same molecule.[3]
Chain-transfer agent: Substance able to react with a chain carrier by a reaction in which the original chain carrier is deactivated and a new chain carrier is generated.[3]
- ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "chain transfer". doi:10.1351/goldbook.C00963
- ^ Flory, P. J. Principles of Polymer Chemistry, Cornell University Press, Ithaca, NY, 1953, p. 136. ISBN 0-8014-0134-8
- ^ a b "Terminology for reversible-deactivation radical polymerization previously called "controlled" radical or "living" radical polymerization (IUPAC Recommendations 2010)". Pure and Applied Chemistry. 82 (2): 483–491. 2010. doi:10.1351/PAC-REP-08-04-03.