ANIONIC POLYMERIZATION is a reaction in which a cationic initiator transfer charge to a monomer followed by a polymerization reaction with remaining monomers. A successive monomer addition result in the formation of active center of a negative ion associated with a positive counter ion. The center typically consists of active carbanion which carries the polymerization. One of the main advantages of living anionic addition polymerization is that it allows controlling structural and compositional features of a polymer. The type of solvents is dictated by the reactivity of the initiator and carbanion of the propagating chain end. This polymerization is commonly used in production of polydiene and styrene-butadiene rubbers as well as thermoplastic styrene-based elastomers.
CATIONIC POLYMERIZATION is a reaction in which a cationic initiator transfers charge to a monomer followed by a polymerization reaction with remaining monomers. A successive monomer addition result in the formation of active center of a positive ion associated with a negative counter ion. In cationic vinyl polymerization the initiator is cation which is attracted to carbon-carbon double bond. Typical cationic polymerization involves two types of monomers: olefins and heterocyclic monomers.
NITROXIDE-MEDIATED RADICAL POLYMERIZATION (NMP) uses alkoxyamines as initiators which form stable free radicals. NMP provides exceptional control over polymer structure and dispersity because nitroxide radicals are stable.