Reversible Addition–Fragmentation Chain Transfer Polymerization

Abstract This article reviews the mechanistic and practical aspects of free radical polymerization with reversible addition–fragmentation chain transfer—the reversible addition–fragmentation chain transfer (RAFT) process. RAFT is conducted by the addition of a thiocarbonylthio compound (ZC(S)SR) to a conventional radical polymerization. Suitable RAFT agents include dithioesters, trithiocarbonates, dithiocarbamates, and xanthates. These thiocarbonylthio compounds confer living characteristics to the radical polymerization by a mechanism of reversible addition–fragmentation chain transfer and provide exceptional control over molecular weight, molecular weight distribution, composition, and architecture of the resulting polymers. The process can be applied to most monomers polymerizable by radical polymerization and offers a convenient route to well‐defined homo‐, gradient, diblock, triblock, and star polymers as well as more complex architectures including microgels and polymer brushes.