Accueil > Séminaires > Précédents séminaires > Double Hydrophilic Block copolymers with Unprecedented Characteristics via Aqueous RAFT/MADIX Polymerization

Double Hydrophilic Block copolymers with Unprecedented Characteristics via Aqueous RAFT/MADIX Polymerization

Mathias Destarac Laboratoire IMRCP, Université Toulouse 3 Paul Sabatier

Nowadays, there is a substantial need for new water soluble polymers with original properties. Reversible-deactivation radical polymerization (RDRP) is one of the most convenient approaches for tailor-making various kinds of hydrophilic polymers with complex architectures. Among the RDRP options available, xanthate-mediated RAFT (also known as RAFT/MADIX) polymerization is a method of choice because of its high tolerance to water and ionic monomers. In contrast with most of other classes of RAFT agents, xanthates allow the synthesis of block copolymers based on monomers of highly disparate reactivities (e.g. acrylamides and N-vinyl monomers). We recently reported the first example of RDRP of N-vinyl pyrrolidone (NVP) in water by means of a RAFT/MADIX redox-initiated process at room temperature in the presence of a O-ethyl xanthate (refs. 1-2). Consequently, several original P(NVP)-based double hydrophilic block copolymers were prepared in pure water (2). We also pushed back the limits of molar mass control in aqueous RAFT/MADIX polymerisation through a fast and quantitative gel polymerisation of a series of acrylamido monomers (3). Unprecedentedly high Mn up to 106 g.mol-1 with low dispersities (Ð < 1.2) were achieved. The reasons for access to abnormally high kinetic chain length in the presence of a RAFT/MADIX agent are discussed. Access to ultra-high molar mass thermoresponsive block copolymers and first results on their rheological properties in water are presented. These findings can open up avenues for fast precision polymer synthesis in environmentally friendly conditions, and above all in ranges of molar masses that were not attainable before.

References

1. A. Guinaudeau, S. Mazières, D. J. Wilson, M. Destarac, Polym. Chem. 2012, 3, 81-84.
2. A. Guinaudeau, S. Sandeau, S. Mazières, O. Coutelier, H. D. Nguyen Thi, V. Le Drogo, D. J. Wilson, M. Destarac, Macromolecules 2014, 47, 41-50.
3. E. Read, A. Guinaudeau, D. J. Wilson, A. Cadix, F. Violleau, M. Destarac, Polym. Chem. 2014, 5, 2202-2207