Synthesis of well-defined star polymers by atom transfer radical polymerization using the core-first approach

Initiators with functionality from 2 to 6 were synthesized from a variety of organic and inorganic precursors. The atom transfer radical polymerization (ATRP) of styrene, acrylates and methacrylates proceeded in a controlled fashion under a variety of conditions providing well-defined star polymers with molecular weights reaching 500,000 as well as star block copolymers. For butyl acrylate polymerizations from initiators containing 2-bromopropionate groups, kinetic arguments were used to demonstrate that initiation was efficient regardless of the initiator functionality. Triple detection size exclusion chromatography also confirmed that target molecular weights could be obtained in butyl acrylate polymerizations.