Iron-mediated AGET ATRP of MMA using acidic/basic salts as reducing agents

Development of Environmentally Friendly Atom Transfer Radical Polymerization

Atom transfer radical polymerization (ATRP) is one of the most successful techniques for the preparation of well-defined polymers with controllable molecular weights, narrow molecular weight distributions, specific macromolecular architectures, and precisely designed functionalities. ATRP usually involves transition-metal complex as catalyst. As the most commonly used copper complex catalyst is usually biologically toxic and environmentally unsafe, considerable interest has been focused on iron complex, enzyme, and metal-free catalysts owing to their low toxicity, inexpensive cost, commercial availability and environmental friendliness. This review aims to provide a comprehensive understanding of iron catalyst used in normal, reverse, AGET, ICAR, GAMA, and SARA ATRP, enzyme as well as metal-free catalyst mediated ATRP in the point of view of catalytic activity, initiation efficiency, and polymerization controllability. The principle of ATRP and the development of iron ligand are briefly discussed. The recent development of enzyme-mediated ATRP, the latest research progress on metal-free ATRP, and the application of metal-free ATRP in interdisciplinary areas are highlighted in sections. The prospects and challenges of these three ATRP techniques are also described in the review.

Addressing the role of triphenylphosphine in copper catalyzed ATRP

A new Atom Transfer Radical Polymerization (ATRP) process with triphenylphosphine (PPh₃) and [Cu^IIMe₆TREN]²⁺ as the catalyst system is reported.

Fe-mediated ICAR ATRP of methyl methacrylate on photoinduced miniemulsion polymerization

The initiators for continuous activator regeneration (ICAR) atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) were investigated in microemulsion under light irradiation with ethyl 2-bromoisbutyrate (EBiB) as an ATRP initiator, ferric chloride hexahydrate (FeCl3·6H2O) as a catalyst, N,N,N′,N′-tetramethyl-1,2-ethanediamine (TMEDA) as a ligand, and azobisisobutyronitrile (AIBN) as an initiator and reducing agent. The linear dependence of ln([M]0/[M]) on polymerization time was observed, indicating that the polymerization was living polymerization. Furthermore, the number-average molecular weights (Mn), gel permeation chromatography (GPC) and molecular weight distributions (MWD) of the PMMA obtained from GPC were controlled. The product was characterized by 1H nuclear magnetic resonance (NMR) and GPC. The living features were verified by chain-extended with MMA with the obtained PMMA as macroinitiator.

Iron-catalyzed atom transfer radical polymerization

This article reviews the preparation of polymers using iron-catalyzed atom transfer radical polymerization.