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.

Living Radical Polymerization by the RAFT Process – A Third Update

“…[332] US Patents on RAFT Table 26 provides a list of granted US patents published during 2009-early 2012 and is an update to the list that appeared in the Encyclopedia of Polymer Science. [551] The list includes three divisionals of the original CSIRO RAFT patent. [637][638][639] …”

“…The data is presented in another form in Table 15. [551] There are several examples that have been reported (see Tables above) which fall outside of these guidelines and where good control (i.e. low dispersities, successful block synthesis) has, nonetheless, been achieved.…”

Living Radical Polymerization by the RAFT Process - A Second Update

“…Work cited in the previous reviews [7,8] is only mentioned again where necessary to put the more recent work in context. The past 2 years has seen the publication of further general reviews detailing the RAFT process which include works by Moad, Rizzardo, and Thang, [9][10][11][12] a Handbook of RAFT Polymerization, [13] and a highlight article by Barner-Kowollik and Perrier [14] on the future of RAFT. Reviews on specific areas include the kinetics and mechanism of RAFT polymerization, [15][16][17][18] the use of RAFT to probe the kinetics of radical polymerization, [19,20] the use of RAFT in organic synthesis, [21] amphiphilic block copolymer synthesis, [22,23] the synthesis of end functional polymers, [24] the synthesis of star polymers and other complex architectures, [25,26] the use of trithiocarbonate RAFT agents, [27] the use of xanthate RAFT agents (MADIX), [28] polymerization in heterogeneous media, [29][30][31][32] RAFT polymerization initiated with ionizing radiation, [33] polymer synthesis in aqueous solution, [34][35][36][37] surface and particle modification, [38,39] synthesis of self assembling and/or stimuli responsive polymers, [36,40] RAFT-synthesized polymers in drug delivery, [22,41] and other applications of RAFTsynthesized polymers.…”

RAFT Polymerization and Some of its Applications

“…A survey of granted US patents in the field of RAFT is included in our recent reviews. [4,21] These patents cover a multitude of applications including polymer therapeutics, drug delivery, biosensors, plastic solar cells, microelectronics, desalination membranes, cosmetics, lubricants, surfactants, paints, inks, and adhesives. In this section we provide a summary of recent research in three specific areas where RAFT polymerization has been applied in developing new materials for optoelectronics, therapeutic delivery, and rheology control.…”