Rapid synthesis of ultrahigh molecular weight and low polydispersity polystyrene diblock copolymers by RAFT-mediated emulsion polymerization

Reversible-deactivation radical polymerization techniques can be used to produce large and complex macromolecules for a wide range of applications. However, RAFT and related techniques are not readily applicable to the synthesis of well-defined, ultrahigh molecular weight polymers from monomers that have a low propagation rate coefficient (such as styrene). Herein we report the use of a novel water-soluble macro-stabilizer in the RAFT-mediated emulsion polymerization of styrene yielding an ultrafast synthesis of ultrahigh molecular weight, low polydispersity polystyrene diblock copolymers to very high conversion. This environmentally friendly emulsion technique produces uniform nanoparticles with precise control over molecular weight and particle size, presenting great potential for many applications.