(143d) Atom Transfer Radical Polymerization Synthesis to Yield Copper-Free Block Copolymers

We report a method of atom transfer radical polymerization (ATRP) for the synthesis of copper-free poly(2-diethylaminoethyl methacrylate (PDEAEM) pentablock copolymers. ATRP is a controlled radical polymerization technique for the development of functional polymers with complex and diverse architectures. Biocompatibility is an increasing concern with growing applications for these polymers synthesized by ATRP in the fields of biology and medicine because of the residual copper catalysts. The reported ATRP synthesis method utilizes novel copper(I) oxide nanoparticles with a polyvinylpyrrolidone coating as catalysts, that can be easily removed after polymerization. We demonstrate this through synthesis of PDEAEM-based pentablock copolymers with pH- and temperature sensitive gelation behavior using a pluronic macrointiator. The copper(I) oxide nanoparticles are easily removed using a column of basic alumina with x-ray spectroscopy (XPS) showing no residual copper in the final product. This ATRP method allows for the synthesis of polymers with low toxicity for in vivo applications such as drug and gene delivery.