Atom transfer radical polymerization (ATRP) of acrylamide (AM) has proved challenging, typically exhibiting low conversions and broad molecular weight distributions (MWDs). Herein, we report the synthesis of well-defined polyacrylamide (both homo and block copolymers) via aqueous copper(0)mediated reversible-deactivation radical polymerization (Cu(0)-RDRP), exploiting the in situ disproportionation of Cu(I)Br in the presence of Me 6 Tren to yield insoluble Cu(0) and Cu(II)Br 2 which acts as a deactivator. Careful optimization of the levels of Cu(I)Br and Me 6 TREN allowed for the synthesis of polyacrylamide of a range of molecular weights (DP n = 20−640) proceeding to quantitative conversion within just a few minutes (typically full conversion is attained within 15 min of reaction time) and exhibiting narrow MWDs (Đ as low as 1.09), which represents a significant improvement over transitional-metalmediated approaches previously reported in the literature. This optimized approach was subsequently utilized to perform in situ chain extensions and block copolymerizations with hydroxyethyl acrylamide, yielding block copolymers of low dispersity and quantitative monomer conversions in a time frame of minutes.

The controlled polymerization of N-isopropyl acrylamide (NIPAM) is reported in a range of international beers, wine, ciders and spirits utilizing Cu(0)-mediated living radical polymerization (SET-LRP). Highly active Cu(0) is first formed in situ by the rapid disproportionation of [Cu(I)(Me 6-Tren)Br] in the commercial water-alcohol mixtures. Rapid, yet highly controlled, radical polymerization follows (Đ values as low as 1.05) despite the numerous chemicals of diverse functionality present in these solvents e.g. alpha acids, sugars, phenols, terpenoids, flavonoids, tannins, metallo-complexes, anethole etc. The results herein demonstrate the robust nature of the aqueous SET-LRP protocol, underlining its ability to operate efficiently in a wide range of complex chemical environments.

Reversible, low temperature aqueous polymerization/depolymerization of acrylamides and acrylates in the presence of dissolved CO2.

E-mail: D.M.Haddleton@warwick.ac.ukDuring recent years we have witnessed the rapid development and understanding of controlled radical polymerization (CRP) methods.The scope of copper-mediated living radical polymerization in particular, has paved the way for the synthesis of a new generation of synthetic precision materials. Several versatile, simple and inexpensive methods have been employed for the synthesis of sequence-controlled multiblock copolymers in a one-pot polymerization reaction at ambient temperature or below. Careful optimization of the reaction conditions allows for monomer sequence and the chain length to be varied upon demand, furnishing complex compositions in a matter of minutes/hours. Perhaps more importantly, these techniques can be utilized for the rapid synthesis of narrow dispersed diblock and triblock copolymers, which are routinely requested for various applications e.g. self-assembly. The potential and the limitations of these methods are presented and discussed.