Halogen Donors in Metal-Catalyzed Living Radical Polymerization:  Control of the Equilibrium between Dormant and Active Species

Ouchi, Makoto; Tokuoka, Shinsuke; Sawamoto, Mitsuo

doi:10.1021/ma702415d

Cited by 7 publications

(8 citation statements)

References 22 publications

(16 reference statements)

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“…to the metal-catalyzed ATRP led to a significant increase in the polymerization rate, presumably due to competition with the ligand for coordination sites and form more efficient catalysts. Another kind of additives for better controllable ATRP by external halogen delivery like molecular iodine (I 2 ), 31 triphenylmethyl chloride (Ph 3 CCl) 32 has also been widely used recently. Very recently, we reported a novel strategy with catalytic amount of inorganic base (NaOH or Fe (OH) 3 ) as the additives to enhance the polymerizaiton rate of the iron-mediated AGET ATRP of styrene using commercially available onium salt, tetrabutylammonium bromide (TBABr), as the ligand.…”

Section: Introductionmentioning

confidence: 99%

Catalytic amounts of sodium hydroxide as additives for iron-mediated AGET ATRP of MMA

et al. 2011

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Section: Introductionmentioning

confidence: 99%

Catalytic amounts of sodium hydroxide as additives for iron-mediated AGET ATRP of MMA

et al. 2011

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“…The evolution of M n and dispersity vs. monomer conversion is portrayed in Figure B. Different from the results in normal ATRP that literature reported, the addition of halogen donors has minimal impact on molecular weight. Moreover, a slightly broader molecular weight distribution is obtained with the addition of halogen donors.…”

Section: Resultsmentioning

confidence: 73%

“…, the Ph 3 C‐Cl can be activated by the low oxidation‐state activator and generate the high oxidation‐state deactivator; this function is similar to the role of dormant species in ATRP equilibrium . Besides, as demonstrated by Sawamoto et al, the activation rate for the Ph 3 C‐Cl is much higher than that of Br‐capped ethyl acrylate, which can be considered as a model of dormant species in ATRP. This point can also be validated by CV results as depicted in Figure .…”

Section: Resultsmentioning

confidence: 82%

“…As described above, the molecular weight of polymers obtained under low catalyst concentration was substantially larger than the theoretically predicted value, which was possibly attributed to inefficient deactivation and slow initiation. However, controllability reportedly could be improved, and the molecular weight became closer to the calculated value by adding halogen donors in a ruthenium‐catalyzed ATRP system . Therefore, we investigated the effect of adding halogen donors on polymerization kinetics in this system.…”

Section: Resultsmentioning

confidence: 96%

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Iron‐based electrochemically mediated atom transfer radical polymerization with tunable catalytic activity

2017

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An iron‐based electrochemically mediated atom transfer radical polymerization (eATRP) system with tunable catalytic activity was developed by adjusting the supporting electrolyte formula. Kinetic behaviors of the systems using four typical supporting electrolytes (namely, TBABr, TBAPF6, TBACl, and TBABF4) were investigated. The type of anions was found to significantly affect the polymerization kinetics. TBAPF6 system proceeded with a considerable polymerization rate, whereas TBABr system showed better controllability. Importantly, the effect of supporting electrolyte on eATRP kinetics (mainly on ATRP equilibrium) was confirmed through kinetic modeling. Furthermore, the effect of catalyst loading using TBAPF6 as supporting electrolyte was also studied, and the results showed an uncontrolled polymerization for catalyst loading lower than 500 ppm. When hybrid supporting electrolyte (TBAPF6/TBABr) was used to tune catalytic activity, the polymerization slows down and the dispersity decreases with the increase in TBABr ratio. Polymers with a narrow molecular weight distribution (dispersity index <1.5) were obtained using 100% TBABr under 100 ppm catalyst. Besides, experimental attempt to improve the controllability by adding halogen donors was made, whereas the halogen donors just prolonged the induction period and no improvement was achieved. As a whole, a deeper understanding of kinetic studies is obtained by these controlled trials. © 2017 American Institute of Chemical Engineers AIChE J, 64: 961–969, 2018

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“…Reversible deactivation radical polymerization (RDRP) [1,2,3,4,5,6,7] including initiator-transfer agent-terminator (Iniferter) [8,9,10,11], nitroxide-mediated polymerization (NMP) [12,13,14,15,16,17,18], atom transfer radical polymerization (ATRP) or metal-catalyzed living radical polymerization [19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43] and reversible addition−fragmentation chain transfer polymerization (RAFT) [44,45,46,47,48,49,50,51,52,53,54,55] has been used to design and synthesize various polymeric structure and architectures extensively. Among those methods, ATRP is the most widely used method and has been used to produce different topological polymers, such as star, brush, block and hyperbranched polymers [56,57,58,59].…”

Section: Introductionmentioning

confidence: 99%

Iron-Mediated Homogeneous ICAR ATRP of Methyl Methacrylate under ppm Level Organometallic Catalyst Iron(III) Acetylacetonate

Jiang

Zhang

et al. 2016

Polymers

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Atom Transfer Radical Polymerization (ATRP) is an important polymerization process in polymer synthesis. However, a typical ATRP system has some drawbacks. For example, it needs a large amount of transition metal catalyst, and it is difficult or expensive to remove the metal catalyst residue in products. In order to reduce the amount of catalyst and considering good biocompatibility and low toxicity of the iron catalyst, in this work, we developed a homogeneous polymerization system of initiators for continuous activator regeneration ATRP (ICAR ATRP) with just a ppm level of iron catalyst. Herein, we used oil-soluble iron (III) acetylacetonate (Fe(acac) 3 ) as the organometallic catalyst, 1,1 1 -azobis (cyclohexanecarbonitrile) (ACHN) with longer half-life period as the thermal initiator, ethyl 2-bromophenylacetate (EBPA) as the initiator, triphenylphosphine (PPh 3 ) as the ligand, toluene as the solvent and methyl methacrylate (MMA) as the model monomer. The factors related with the polymerization system, such as concentration of Fe(acac) 3 and ACHN and polymerization kinetics, were investigated in detail at 90˝C. It was found that a polymer with an acceptable molecular weight distribution (M w /M n = 1.43 at 45.9% of monomer conversion) could be obtained even with 1 ppm of Fe(acac) 3 , making it needless to remove the residual metal in the resultant polymers, which makes such an ICAR ATRP process much more industrially attractive. The "living" features of this polymerization system were further confirmed by chain-extension experiment.

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Halogen Donors in Metal-Catalyzed Living Radical Polymerization: Control of the Equilibrium between Dormant and Active Species

Cited by 7 publications

References 22 publications

Catalytic amounts of sodium hydroxide as additives for iron-mediated AGET ATRP of MMA

Catalytic amounts of sodium hydroxide as additives for iron-mediated AGET ATRP of MMA

Iron‐based electrochemically mediated atom transfer radical polymerization with tunable catalytic activity

Iron-Mediated Homogeneous ICAR ATRP of Methyl Methacrylate under ppm Level Organometallic Catalyst Iron(III) Acetylacetonate

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