Organometallic-mediated radical polymerization for the precision design of novel poly(ionic liquid) copolymers in water

In recent years, poly(ionic liquid)s (PIL)s were found to take an enabling role in important fields of polymer chemistry and material science. PILs combine the unique properties of ionic liquids with the flexibility and properties of macromolecular architectures giving rise to a new family of functional polymers that opens new area of applications such as polymer electrolytes in electrochemical devices, powerful dispersants and stabilizers, absorbing membranes, precursors for carbon materials, porous polymers, etc. Controlled radical polymerization techniques have recently emerged as powerful tools for the precision design of novel PILs architectures and functionalities, enabling a considerable extension of the applications of PILs with the emergence of new properties. Many efforts are devoted to tentatively control the radical polymerization of ionic liquid monomers (ILs) that directly leads to PILs without requiring further polymer derivatization. Poly(vinyl imidazolium)s belong to a class of PILs of high interest but the control radical polymerization of their corresponding monomer is touchy due to the high reactivity of their propagating radical. In this communication, we will report on the implementation of organometallic-mediated radical polymerization (OMRP) technique for the precision synthesis of unprecedented PILs (co)polymers by direct polymerization of ILs in water. We will first discuss how a commercially available cobalt complex can efficiently control the growth of poly(vinyl imidazolium) chains and lead to PILs with predicted molar masses and low dispersities under mild experimental conditions. The efficiency of the process will then be illustrated by the one-pot synthesis of vinyl imidazolium-based block copolymers in aqueous media. This OMRP technique, highly compatible to water and active under moderate temperatures (30-40°C), is unique for providing well-defined vinyl imidazolium based-copolymers and novel PILs assemblies, and open new application fields.