Surface-Enriched Trithiocarbonate-Functionalized Block Copolymer Nanoparticles via Orthogonal RAFT Dispersion...

Herein, we develop poly(trithiocarbonate)-based macromolecular reversible addition-fragmentation chain transfer (macro-RAFT) agents synthesized by green light-activated photoiniferter polymerization of 2-(2-(n-dodecyltrithiocarbonate)propionate)ethyl methacrylate, which retain pendant trithiocarbonate groups and exhibit excellent solubility in n-dodecane. These macro-RAFT agents enable well-controlled RAFT dispersion polymerization of benzyl methacrylate in n-dodecane, producing well-defined diblock copolymers and nanoparticles bearing coronas densely functionalized with unreacted trithiocarbonate units. The surface-localized RAFT moieties provide landscape for surface-initiated polymerization, imparting a high level of functionalization to the resulting nanoparticles. Moreover, spherical nanoparticles can act as multifunctional cores for divergent growth of poly(N,N-dimethylacrylamide) arms via photoinduced electron/energy transfer-RAFT (PET-RAFT) polymerization, giving star polymers with tunable size and very high arm numbers. This study provides a general route to RAFT-active nanoparticles for postpolymerization modification and star polymer synthesis.