Controlled/"Living" Radical Polymerization. Halogen Atom Transfer Radical Polymerization Promoted by a Cu(I)/Cu(II) Redox Process

Abstract

An extension of atom transfer radical addition, ATRA, to atom transfer radical polymerization, ATRP, provided a new and efficient way to conduct controlled/"living" radical polymerization. By using a simple alkyl halide, R-X (X = Cl and Br), as an initiator and a transition metal species complexed by suitable ligand(s), Mt"/L*, e.g., CuX/2,2'-bipyridine, as a catalyst, ATRP of vinyl monomers such as styrenes and (meth)acrylates proceeded in a living fashion, yielding polymers with degrees of polymerization predetermined by A[M]/[I]0 up to M" to 105 and low polydispersities, 1.1 < MJMn < 1.5. The participation of free radical intermediates was supported by analysis of the end groups and the stereochemistry of the polymerization. The general principle and the mechanism of ATRP are elucidated. Various factors affecting the ATRP process are discussed.

Chemical analysis and aqueous solution properties of charged amphiphilic block copolymers PBA-b-PAA synthesized by MADIX®

“…The other major limitation of anionic synthesis process comes from the narrow range of chemical compounds that can be properly polymerized (PB, PS, PI, PtBA, PMMA and PEO). Fortunately, in the last decade, controlled radical polymerizations [1] like RAFT [2] and ATRP [3,4] have been developed as an alternative route to block copolymer synthesis, opening a new era for block copolymer science and industry. These processes allow relatively cheap and large-scale production of block copolymers out of a wide variety of chemistries.…”

Synthesis and Single Molecule Force Spectroscopy of Graft Copolymers of Poly(2-hydroxyethyl methacrylate-g-ethylene glycol)

“…PHEMA is also expected to have some hydrophobic interactions between -CH 2 -groups and a high van der Waals attractive interaction, since it is reported to have a high refractive index of 1.512. 23 The technique of atom transfer radical polymerization (ATRP) [26][27][28][29][30][31][32][33][34][35] was chosen to synthesize the poly(HEMAg-EG) model system described in this paper for a number of reasons. ATRP is an excellent general method to synthesize statistical, gradient, block, and graft copolymers as well as star and hyperbranched polymers due to the facile availability of functional monomers, halogen initiators, and catalysts.…”

Purification of Peptides in High-Complexity Arrays

“…[132] Cu II was applied as an inhibitor to slow down the reaction rates which had already been considered beneficial for the control of the polymerization by WANG and MATYJASZEWSKI in 1995. [133] Since then, the addition of Cu II as a deactivating species has been extensively studied, but precise strategies to completely control the polymerization rates in siATRP are still under investigation. [80] For example, KIMANI and MORATTI described a three times reduced reaction rate over 24 h of polymerization for their CuBr/CuCl2/PMDETA (0.5:0.5:1 eq) catalyst system in TEGMME.…”