Anionic Graft Polymerisation of Styrene from Polyisoprene. Dependence of Grafting Efficiency on Polyisoprene Structure

Styrene was grafted from polyisoprene forming poly(isoprene-g-styrene) graft polymers. N,N,N',N'-Tetramethylene diamine and s-butyllithium were used to create active centres on the polyisoprene backbone in cyclohexane under anionic living polymerisation conditions. The stereoregularity of polyisoprene is shown to influence the grafting efficiency. Addition of small amounts of tetrahydrofuran increased grafting efficiency and decreased polydispersity of the graft polymers obtained. Polystyrene branches are shown to be syndiotactic rich.