(416a) Crosslinked Polymeric Nanoparticles Via Brush Copolymers

Well-defined core-shell brush block copolymers were prepared by tandem ring-opening metathesis polymerization (ROMP) and living radical polymerization (LRP), and used as unimolecular templates for the synthesis of polymer-based nanoparticles. Several bifunctional compounds, containing a norbornene functionality and an alkoxyamine, haloester, or trithiocarbonate functionality, were synthesized. ROMP of these compounds gave well-defined polyfunctional macroinitiators or macro-chain transfer agents for LRP. Sequential LRP of different monomers using these macroinitiators or macro-chain transfer agents yielded core-shell brush block copolymers with controlled macromolecular architectures. The entire synthetic procedure of core-shell brush block copolymers could be simplified by one-pot sequential ROMP and LRP based on their excellent compatibility. Shell-crosslinked nanoparticles were prepared by selectively crosslinking the shell domains of core-shell brush block copolymers, and nanocages were further obtained by degradation of the core domains of these nanoparticles. Core-crosslinked nanoparticles with controlled shape and size were also synthesized by selectively crosslinking the core domains of core-shell brush block copolymers.

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