Anionic Chain-Growth Polymerization: Overview

Anionic polymerization is a form of addition or chain-growth polymerization that proceeds via a carbanion intermediate.

Typically, for anionic polymerization, the initiator is a strong nucleophile such as an organolithium or Grignard reagent.

The monomers undergoing anionic polymerization must be ethylene derivatives with  one or two electron‐withdrawing groups.

The electron‐withdrawing substituent stabilizes the carbanion intermediate generated during the polymerization process.

Polyacrylonitrile, polyvinyl chloride, and polystyrene, commonly used to produce textile fibers, garbage bags, and foam cups, respectively, are anionic polymers derived from monomers with one electron‐withdrawing group.

The presence of more than one electron‐withdrawing group makes the monomer highly reactive. Consequently, even weak nucleophiles can initiate the polymerization process.

For instance, methyl-⍺-cyanoacrylate is a monomer with two functional groups. Even trace amounts of water in the surroundings can initiate its rapid polymerization into superglue, a powerful adhesive.