Organometallic-mediated radical polymerization, a versatile tool for the precision synthesis of unprecedented copolymers

Controlled radical polymerization techniques give access to innovative (multi)functional polymeric materials for advanced applications. Organometallic-mediated radical polymerization (OMRP) is one of these techniques that enable the preparation of unprecedented copolymers, and is based on the temporary deactivation of the propagating chains by a transition metal complex. The strength of the carbon-metal bond at the polymer chain-end is dictating the reactivity of the system. One of the most efficient OMRP process involves the commercially available Co(acac)2. Recent studies have demonstrated that the system reactivity is easily modulated by the addition of some molecules able to coordinate the cobalt complex, by tuning the temperature, or by UV irradiation. The facile modulation of the C-Co bond strength has enabled to control the polymerization of monomers of opposite reactivity, such as vinyl esters and acrylates, and to synthesize novel well-defined (co)polymers under very mild experimental conditions. In this talk, we will discuss some recent breakthroughs in the field that illustrate the huge potential of the process for the design of unique functional macromolecules. More precisely, we will describe the first control of the copolymerization of ethylene with a series of functional vinyl monomers under mild experimental conditions that leads to random copolymers with ethylene content up to 60 mol% and negligible chain branching. The first one-pot synthesis of novel ethylene-based block copolymers will also be discussed. Additionally, we will demonstrate the implementation of the OMRP process to aqueous based media by describing, amongst other examples, the precision synthesis of innovative functional (telechelic) poly(ionic liquid)s (PILs) in water.