US EPA

6613296 

Journal Article 

Living radical polymerization based on transition metal complexes 

Sawamoto, M; Kamigaito, M; , 

1996 

ELSEVIER SCI LTD 

OXFORD 

371-377 

WOS:A1996VV10400004 

Precise control of radical polymerization has been considered difficult for a long time because of the high reactivity and low selectivity of the radical growing species. This image has recently been changed by the development of living or controlled radical polymerizations. Though differing in initiating systems and other details, these radical processes apparently rely on the reversible formation (thermally, photochemically or via transition metal complexes) of reactive radical growing species from dormant covalent species. This review primarily discusses living radical polymerizations with transition metal complexes of ruthenium, copper, etc,. which involve the generation of the radical species from dormant carbon-halogen bonds via the redox reaction at the metal center. This new type of living radical polymerization can be applied around 60-130 degrees C to most commercially available monomers such as styrene, methacrylates and acrylates, even in the presence of water and alcohols, to give polymers with controlled molecular weights and narrow molecular weight distributions. Such transition-metal-based systems can also afford polymers with controlled architectures, including end-functionalized, block and multiarmed polymers.