ICAR ATRP with ppm Cu Catalyst in Water

Abstract

Initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) with ppm amount of Cu catalyst was successfully developed in water. For the first time, Cu catalyst concentrations of 100 ppm and lower were used in aqueous media to prepare well-defined macromolecules. Polymers of oligo(ethylene oxide) methyl ether acrylate were synthesized with low dispersity (M w /M n = 1.15−1.28) using 20−100 ppm of an active CuBr/tris(pyridin-2-ylmethyl)amine-based catalyst in the presence of excess bromide anions. This technique was used to synthesize a thermoresponsive block copolymer of poly(oligo(ethylene oxide) methyl ether methacrylate)-b-poly(oligo(ethylene oxide) methyl ether acrylate). The methacrylic block had a lower critical solution temperature (LCST = 77 ± 2 °C) below that of the acrylic block. The hydrodynamic diameter of ca. 10 nm at temperatures below the LCST is consistent with free polymer chains in solution, and the diameter of ca. 30 nm above the LCST is consistent with a micellar structure. The aqueous ICAR ATRP technique was also used to successfully synthesize a well-defined bioconjugate by growing poly(oligo(ethylene oxide) acrylate) from a bovine serum albumin (BSA) protein functionalized with ca. 30 ATRP initiating sites.

Computer‐Aided Optimization of Conditions for Fast and Controlled ICAR ATRP of n‐Butyl Acrylate

“…For instance, it was demonstrated that, depending on the ATRP catalyst reactivity, step-wise addition of conventional radical initiator in the ICAR ATRP of methyl methacrylate and styrene is needed to reach high conversion while still obtaining a good livingness and control over chain length with ppm levels of ATRP catalyst. Moreover, Konkolewicz et al [56] recently reported for the first time the successful ICAR ATRP of oligo(ethylene oxide) methyl ether acrylate in water using a low (<100) ppm level of ATRP catalyst further proving the importance of this modified ATRP technique for a broad range of monomers and in particular acrylates. Additionally, the potential of ICAR ATRP for the controlled production of polyacrylates can be inferred from the new polymeric materials prepared via normal ATRP.…”

“…[56][57][58][62][63][64] Such information is crucial for a comparison of these techniques to evaluate their potential industrial application, since the ultimate goal of a CRP technique is to produce a wide range of average chain lengths at acceptable polymerization rates while preserving control over PDI and EGF. In this work, such detailed kinetic modeling study is presented for the bulk ICAR ATRP of nBuA using the commercially available N,N,N 0 ,N 00 ,N 00 -pentamethyldiethylenetriamine (PMDETA)…”

Plastic antibody for DNA damage: fluorescent imaging of BPDE–dG adducts in genomic DNA

“…The homogeneity of binding sites and the mass transfer were greatly improved in virtue of the well-dened nanostructure, which was constructed by ICAR-ATRP (Scheme 1). 35,[42][43][44] We further demonstrated that this nanoMIP could be applied as a plastic antibody for direct uorescent imaging of BPDE-ssDNA adducts in genomic DNA isolated from cultured cancer cells.…”

Fed-Batch Control and Visualization of Monomer Sequences of Individual ICAR ATRP Gradient Copolymer Chains

“…Additionally, the activator is oxygen sensitive implying stringent experimental procedures with respect to oxygen removal and the high ATRP catalyst amounts lead to intensive purification processes. Hence, more recently modified ATRP techniques have been developed in which a low ATRP catalyst amount is used and activator is (re)generated from the oxygen insensitive deactivator through an external source, e.g., an electrode or a reducing agent) [11,[16][17][18][19][20][21]. With these modified techniques, an ATRP catalyst level of ca.…”

“…For less active catalysts, single or multiple discrete addition(s) of conventional radical initiator can be required to ensure a high conversion. More recently, ICAR ATRP has been also successfully applied with ATRP catalysts made of other transition metals than Cu [23] and in water [21]. Scheme 1.…”