Well-defined PDMAEA stars via Cu(0)-mediated reversible deactivation radical polymerization

The Cu(0)-mediated reversible deactivation radical polymerization of N,N′-dimethylaminoethyl acrylate in DMSO and IPA at ambient temperature using Cu(0) wire is investigated. Tetra- and octafunctional initiators were utilized to facilitate the synthesis of well-defined PDMAEA star homo and block copolymers with a range of molecular weights (M_n ∼ 5000-41 000 g mol^-1). Both solvents demonstrated to be excellent media for the controlled polymerization of DMAEA, yielding narrow molecular weight distributions (∼ 1.1) when the reactions were ceased at ∼40% conversion. Interestingly, at high conversions (typically >55%) high and low molecular weight shoulders were evident by SEC when DMSO and IPA were used, respectively, suggesting a large extent of termination and/or side reactions at prolonged reaction times. Nevertheless, high end group fidelity could be maintained when immediate precipitation of the polymers (at lower conversion) was performed, yielding low dispersed P(DMAEA-b-MA) star block copolymers (< 1.19, M_n ∼ 20 000 g mol^-1). Importantly, guidelines on how to prevent hydrolysis, termination, and side reactions of PDMAEA as well as how to purify and store such materials are also provided and discussed.