Anionic polymerization of N-vinylcarbazole with alkyllithium as an initiator

The anionic polymerization of N-vinylcarbazole (NVC) with alkyllithium (RLi) as an initiator was achieved for the first time. The yield of poly(N-vinylcarbazole) (PNVC) was considerably affected by the molar ratio of RLi to NVC. The polymerization temperature, type of solvent, additives, and type of initiator influenced the anionic polymerization of NVC. The highest yield was obtained with tert-butyllithium (t-BuLi) as an initiator, with a molar ratio of approximately [t-BuLi](0)/[NVC](0) = 0.1. Aliphatic hydrocarbons with relatively low solubility for NVC and PNVC were considered to be appropriate solvents for the anionic polymerization of NVC. The H-1 NMR spectrum strongly supports the polymer chain structure of PNVC. The coordination of NVC nitrogen atoms to the lithium atoms of RLi presumably reduces the electron density of the vinyl group, and the anionic polymerization of NVC becomes possible.