| Abstract: | Vinyl polymerizations initiated by lithium organocuprates under several conditions were investigated. It was observed that this catalyst was effective in the polymerization of specific monomers such as α,β-unsaturated nitrile and carbonyl analogues. The rate of polymerization was rapid but retarded by the addition of pyridine, nitrobenzene, or hydroquinone. Polymerization of methyl methacrylate (MMA) with lithium di-n-butylcuprate as initiator produces predominantly isotactic poly(methyl methacrylate) (PMMA) in toluene. The overall activation energy was estimated as 3.5 kcal/mol deg. Lithium di-n-butylcuprate exerts a higher stereoregulating effect on the addition of monomers than other organolithium initiators. It is proposed that polymerization proceeds via a coordinated anionic mechanism. |
