Patxi Garra,Céline Dietlin, Fabrice Morlet-Savary, Frédéric Dumur, Didier Gigmes, Jean-Pierre Fouassier, Jacques Lalevée
Redox polymerizations are of huge importance throughout academic and industrial polymer science. Many authors propose the reaction of reducing (Red) and oxidizing (Ox) agents to accelerate/initiate radical or cationic polymerizations. As a result of activation energies typically below 80 kJ/mol, such reactions can occur under mild conditions, e.g., at room temperature, with reduced energy consumptions and robust in applications, such as the fabrication of composites. However, a clear definition of redox polymerization can only be found in reviews dealing with redox free radical polymerizations (FRP) published twenty years ago (or more). Therefore, a fresh and broader update is provided here for more recent work. The concepts involved when the « Red » and « Ox » agents constituting the redox initiating system are mixed under mild conditions are presented, followed by a discussion of the redox FRP initiating systems in bulk. Initiating systems dealing with the redox cationic polymerization (CP) are reviewed, and parallels between conventional FRP/CP and controlled polymerizations, in which redox systems are used, is provided. Many redox agents are useful in both modes. Finally, dual-cure (redox/photochemical ; redox dual FRP/CP) systems is presented and selected applications are reviewed. Altogether, the state of the art for redox two-component polymerizations is provided, along with some perspectives.