TRIALLYLSTANNYLLITHIUM-ALLYLLITHIUM AS AN INITIATOR FOR THE ANIONIC REVERSIBLE CHAIN TRANSFER POLYMERIZATION OF 1,3-BUTADIENE

The anionic polymerization of 1,3-butadiene using a novel metalloidal anion initiator, triallylstannyllithium (TALi)-allyllithium (ALi), was studied. The TALi-ALi initiated anionic polymerization of 1,3-butadie ne gave the star polymer along with the linear polybutadiene (PBD). Th e star polymer consisted of three PBD branches and a central tin atom. What is striking is a fact that the number-average molecular weights (M(n)) and molecular weight distribution of three PBD branches and lin ear PBD were almost identical. A reversible chain transfer polymerizat ion mechanism, which includes the equilibrium between tri(macroallyl)s tannyllithium and macroallylic anion, is proposed. (C) 1996 John Wiley & Sons, Inc.