Anionic Polymerization Alkene must have an electron-withdrawing group like C=O,C=N,or NO2. Initiator:Grignard or organolithium reagent. Initiation step:The initiator adds to the monomer to the form an anion. H H CN CN Bu-Li+ →Bu Lit H H butyllithium acrylonitrile stabilized anion => Propagation step:Another molecule of monomer adds to the chain. CN H CN H H H HH」n growing chain acrylonitrile elongated chain polymerChapter 26 9 Anionic Polymerization • Alkene must have an electron-withdrawing group like C=O, CN, or NO2 . • Initiator: Grignard or organolithium reagent. =>