Surface-Dependent Kinetics of Cu(0)-Wire-Catalyzed Single-Electron Transfer Living Radical Polymerization of Methyl Acrylate in DMSO at 25 °C

Abstract

The effect of Cu(0) wire dimensions on the Cu(0) wire/Me 6 -TREN-catalyzed heterogeneous singleelectron transfer living radical polymerization (SET-LRP) of methyl acrylate (MA) initiated with methyl 2-bromopropionate (MBP) in DMSO at 25 °C was analyzed by kinetic experiments. These kinetic results were compared with those of Cu(0) powder/Me 6 -TREN-catalyzed SET-LRP. Both wire and powder produce perfect SET-LRP with a first-order rate of polymerization in growing species up to 100% conversion. Nevertheless, Cu(0) wire experiments demonstrated SET-LRP with greater perfection, allowing for the accurate determination of the external rate order (vis-a `-vis surface area) for heterogeneous Cu(0) catalyst and accurate prediction of k p app from wire dimension. Cu(0) wire also exhibited a significantly greater control of molecular weight distribution than Cu(0) powder. The combined advantages of easier catalyst preparation, handling, predictability, tunability, simple recovery/recycling, and enhanced control of molecular weight distribution make Cu(0)-wire-catalyzed SET-LRP the ideal methodology for the synthesis of tailored polyacrylates.

Aqueous SET-LRP catalyzed with “in situ” generated Cu(0) demonstrates surface mediated activation and bimolecular termination

“…3 Subsequently, SET-LRP was expanded to acrylates, [4][5][6][7][8][9][10][11][12][13][14][15][16][17] methacrylates, 8,[18][19][20][21][22][23][24][25] acrylamides, [26][27][28][29][30][31] methacrylamide, 32 acrylonitrile, 33,34 and monomers containing more complex water soluble side groups, such as sugars, 35,36 N-(2-hydroxypropyl) methacrylamide, 32 dimethylacrylamide, 26 N-isopropylacrylamide, 26,[37][38][39] oligo(ethylene oxide) methyl ether acrylate, 40 oligo(ethylene oxide) methyl ether methacrylate, 41 hydroxyethyl acrylate, 10 hydroxyethyl methacrylate 23 and acryloyl morpholine. 42 At the same time as these developments, the list of solvents used in SET-LRP was expanded to other solvents that in combination with aliphatic N-donor ligands, such as tris[(2-dimethylaminoethyl)...…”

“…10 42 exhibit amplified adsorption and desorption processes that may complement the previous studies on the elucidation of the role of the surface of Cu(0) catalyst on the activation and deactivation steps of SET-LRP. 11,[58][59][60][61] This publication reports the aqueous SET-LRP of HEA and OEOMEA mediated by "in situ" generated Cu(0) catalyst. 26,37,38 The study reported here demonstrates that the surface of Cu(0) is responsible both for the activation of the initiator and dormant growing species, as well as for the much lower extent of bimolecular termination observed during polymer synthesis by SET-LRP.…”

Well-Defined PDMAEA Stars via Cu(0)-Mediated Reversible Deactivation Radical Polymerization

“…44,45 In addition, none of the aforementioned reports, including Cu(0)-mediated RDRP have been employed for the synthesis of PDMAEA star homo and block copolymers.…”

Recent developments in metal-catalyzed living radical polymerization

“…17,61,62 More recently, Percec and co-workers proposed that the Cu(0)-based living radical polymerization proceeds via a single-electron transfer mechanism under certain conditions and that their systems are highly effective for the very fast living radical polymerization of various monomers, leading to well-controlled high-molecular weight polymers with narrow MWDs. [63][64][65][66] In contrast, the Cu(I)-based systems in the presence of reducing agents, such as tin(II) 2-ethylhexanoate, ascorbic acid, Cu(0) and radical initiators, also induced an efficient living radical polymerization, in which the accumulated Cu(II) species changed into the active Cu(I) species via the reduction by these additives. [67][68][69][70] Although the working mechanisms of Cu(0) are still controversial and may depend on the conditions, it is clear that the use of lower oxidation metal species is important for constructing highly catalytic systems.…”