Improvement of the control over SARA ATRP of 2-(diisopropylamino)ethyl methacrylate by slow and continuous addition of sodium dithionite

Aqueous supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) using inorganic sulfites was successfully carried out for the first time. Under optimized conditions, a well-controlled poly[oligo(ethylene oxide) methyl ether acrylate] (POEOA) was obtained with <30 ppm of soluble copper catalyst using tris(2-pyridylmethyl)amine (TPMA) ligand in the presence of an excess of halide salts (e.g. NaCl). Inorganic sulfites (e.g. Na2S2O4) were continuously fed into the reaction mixture. The mechanistic studies proved that these salts can activate alkyl halides directly and regenerate the activator complex. The effects of the feeding rate of the SARA agent (inorganic sulfites), ligand and its concentration, halide salt and its concentration, sulfite used, and copper concentration, were systematically studied to afford fast polymerizations rates while maintaining the control over polymerization. The kinetic data showed linear first-order kinetics, linear evolution of molecular weights with conversion, and polymers with narrow molecular weight distributions (Đ ~1.2) during polymerization even at relatively high monomer conversions (~80%). “One-pot” chain extension and “one-pot” block copolymerization experiments proved the high chain-end functionality. The polymerization could be directly regulated by starting or stopping the continuous feeding of the SARA agent. Under biologically relevant conditions, the aqueous SARA ATRP using inorganic sulfites was used to synthesize a well-defined protein-polymer hybrid by grafting of P(OEOA480) from BSA-O-[iBBr]30.

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“…62 The substitution of TPMA for Me 6 TREN, a L binding stronger to Cu(II) but weaker to Cu(I), 47,62 (Fig. 1(d, e and f), ESI Fig.…”

Section: Resultsmentioning

confidence: 96%

Aqueous SARA ATRP using inorganic sulfites

Abreu

Carmali

et al. 2017

Polym. Chem.

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“…Supplemental activator and reducing agent (SARA) ATRP is one of the most recent developed ATRP variations and it is considered to be a very attractive technique since it allows the use of a low concentration of soluble catalyst (e.g., 100 ppm). With this approach, zero valent metals or Food and Drug Administration (FDA)‐approved inorganic sulfites have been successfully used as SARA agents. The role of these species is to continuously regenerate the activator (e.g., CuX; X: halide) by deactivator reduction (e.g., CuX 2 ) and to slowly generate growing radicals by supplemental activation (Scheme ) …”

Section: Introductionmentioning

confidence: 99%

“…This strategy aims to potentiate the implementation of ATRP at an industrial scale, as well as to provide harmless reaction conditions for the preparation of polymers for the biomedical field. On this matter, it is worth to notice that the SARA ATRP of acrylates, methacrylates, and acrylamides has also been successfully performed in alcohol/water mixtures or even in aqueous medium …”

Section: Introductionmentioning

confidence: 99%

Cyclopentyl methyl ether: A new green co‐solvent for supplemental activator and reducing agent atom transfer radical polymerization

Maximiano

Mendes

Mendonça

et al. 2015

J. Polym. Sci., Part A: Polym. Chem.

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A new green solvent, cyclopentyl methyl ether (CPME), is used for the first time in solvent mixtures for the successful supplemental activator and reducing agent atom transfer radical polymerization (SARA ATRP) of both activated and non‐activated monomers. The SARA ATRP of methyl acrylate (MA), glycidyl methacrylate (GMA), styrene (Sty), and vinyl chloride (VC) in CPME‐based mixtures is studied and presents similar features to those reported in the literature using other SARA ATRP systems. Moreover, CPME‐based mixtures are suitable solvents for the controlled SARA ATRP of MA using different SARA agents, such as Fe(0), Cu(0), or Na2S2O4. The chemical structure and the retention of the chain‐end functionality of the polymers are confirmed by 1H NMR and MALDI‐TOF analyses and the preparation of a well‐defined PMA‐b‐PVC‐b‐PMA triblock copolymer. The method reported here presents an additional improvement in the search for new ecofriendly ATRP systems. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2722–2729

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“…Sodium dithionite (Na 2 S 2 O 4 ) is a well‐known reducing agent, which has been previously used by our group as SARA agent for the SARA ATRP of different monomers in both organic and aqueous media near room temperature conditions . This inexpensive inorganic salt is also known for its ability to scavenge oxygen molecules .…”

Section: Resultsmentioning

confidence: 99%

Self‐degassing SARA ATRP mediated by Na₂S₂O₄ with no external additives

Oliveira

Mendonça

Serra

et al. 2019

Journal of Polymer Science

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The supplemental activator and reducing agent (SARA) atom transfer radical polymerization (ATRP) mediated by Na2S2O4 in the presence of air, without external deoxygenation or additional oxygen scavengers, is reported for several vinyl monomers: methyl acrylate (MA), n‐butyl acrylate (n‐BA), methyl methacrylate (MMA), 2‐(dimethylamino)ethyl methacrylate (DMAEMA), poly(ethylene glycol) methyl ether acrylate (OEOA), and styrene (Sty). The polymerizations can be conducted in aqueous medium or using organic/water mixtures as solvent, with low concentration of copper, near room temperature. In the absence of any external deoxygenation, several well‐defined homopolymers and block copolymers were obtained (Ð < 1.3). The evolution of the oxygen concentration during the polymerizations was monitored with an optical oxygen sensor. The consumption of oxygen prior polymerization in ethanol/water mixtures was attributed to the combined presence of Na2S2O4 and alkyl halide initiator, which led to a lower initiation efficiency (Ieff). This could be overcome by decreasing the headspace volume of the reaction. The system reported exhibited the potential to be scalable, which is very relevant from an industrial standpoint. © 2019 Wiley Periodicals, Inc. J. Polym. Sci. 2020, 58, 145–153

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Improvement of the control over SARA ATRP of 2-(diisopropylamino)ethyl methacrylate by slow and continuous addition of sodium dithionite

Abstract: The kinetics and detailed mechanism of SARA ATRP of 2-(diisopropylamino)ethyl methacrylate (DPA) were investigated.

Cited by 31 publications

References 50 publications

Aqueous SARA ATRP using inorganic sulfites

Aqueous SARA ATRP using inorganic sulfites

Cyclopentyl methyl ether: A new green co‐solvent for supplemental activator and reducing agent atom transfer radical polymerization

Self‐degassing SARA ATRP mediated by Na₂S₂O₄ with no external additives

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Improvement of the control over SARA ATRP of 2-(diisopropylamino)ethyl methacrylate by slow and continuous addition of sodium dithionite

Abstract: The kinetics and detailed mechanism of SARA ATRP of 2-(diisopropylamino)ethyl methacrylate (DPA) were investigated.

Cited by 31 publications

References 50 publications

Aqueous SARA ATRP using inorganic sulfites

Aqueous SARA ATRP using inorganic sulfites

Cyclopentyl methyl ether: A new green co‐solvent for supplemental activator and reducing agent atom transfer radical polymerization

Self‐degassing SARA ATRP mediated by Na2S2O4 with no external additives

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Self‐degassing SARA ATRP mediated by Na₂S₂O₄ with no external additives