Mechanistic Aspects of Nitroxide-Mediated Controlled Radical Polymerization of Styrene in Miniemulsion, Using a Water-Soluble Radical Initiator

Farcet, Céline; Lansalot, Muriel; Charleux, Bernadette; Pirri, Rosangela; Vairon, Jean‐Pierre

doi:10.1021/ma000952p

Cited by 117 publications

(109 citation statements)

References 42 publications

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“…Several studies have been done about this topic, [24][25][26][27][28][29][30][31][32][33][34][35][36] which have identified additional reactions and phenomena related to the TEMPO radical. The work of Sald ıvar-Guerra et al [29] considers a mechanism involving dimer formation and the consequent consumption of TEMPO.…”

Section: Resultsmentioning

confidence: 99%

Mathematical Modeling of NMRP of Styrene–Divinylbenzene over the Pre‐ and Post‐Gelation Periods Including Cyclization

Aguiar

Gonçalves

Pinto

et al. 2013

Macro Reaction Engineering

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Nitroxide-mediated polymerization of styrene-divinylbenzene has been modeled using generating functions of length distributions, pseudo-kinetic propagations, and numerical fractionation with the crosslinking rate depending on generation. Cyclization reactions are tackled by balances of sequences, yielding fair predictions of the measured pendant double bond concentration. With reduction in crosslinking, agreement for the experiments at 90 8C between predicted and measured weight-average, molecular weight, and weight fraction of gel is observed. A much higher relative crosslinking reactivity is observed at 130 8C as compared to 90 8C, likely an effect of the chain mobility.

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Section: Resultsmentioning

confidence: 99%

Mathematical Modeling of NMRP of Styrene–Divinylbenzene over the Pre‐ and Post‐Gelation Periods Including Cyclization

Aguiar

Gonçalves

Pinto

et al. 2013

Macro Reaction Engineering

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“…There is interest in performing NMP in heterogeneous systems, in particular miniemulsion, [1,2,[6][7][8][9][10][11][12][13] because of the benefits gained by operating in a water-based medium (e.g., lower operating viscosities, improved heat transfer, and reduced need for solvents). The mechanisms involved in miniemulsion polymerization are similar to conventional emulsion polymerization, with the primary difference being that submicron monomer droplets (50-300 nm in diameter) act as the primary nucleation and polymerization locus, instead of monomer-swollen micelles.…”

Section: Introductionmentioning

confidence: 99%

Interfacial Mass Transfer in Nitroxide-Mediated Miniemulsion Polymerization

John

Cunningham

McAuley

et al. 2002

Macromol. Theory Simul.

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A mathematical model has been developed to describe the interfacial mass transfer of TEMPO in a nitroxide‐mediated miniemulsion polymerization (NMMP) system in the absence of chemical reactions. The model is used to examine how the diffusivity of TEMPO in the aqueous and organic droplet phases, the average droplet diameter and the nitroxide partition coefficient influences the time required for the nitroxide to reach phase equilibrium under non‐steady state conditions. Our model predicts that phase equilibrium is achieved quickly (< 1 × 10−4 s) in NMMP systems under typical polymerization conditions and even at high monomer conversions when there is significant resistance to molecular diffusion. The characteristic time for reversible radical deactivation by TEMPO was found to be more than ten times greater than the predicted equilibration times, indicating that phase equilibrium will be achieved before TEMPO has an opportunity to react with active polymer radicals. However, significantly longer equilibration times are predicted, when average droplet diameters are as large as those typically found in emulsion and suspension polymerization systems, indicating that the aqueous and organic phase concentrations of nitroxide may not always be at phase equilibrium during polymerization in these systems.

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“…Recently, significant progress has been made in the field of living free radical polymerization including nitroxide-mediate stable free radical polymerization (SFRP); [19][20][21][22][23] atom transfer radical polymerization (ATRP); [24][25][26] and reversible addition-fragmentation transfer (RAFT) process. 27,28 In these polymerizations, there is a fast equilibrium between propagating radiScheme 1. cals and dormant chains, which is prerequisite for the synthesis of controlled polymers.…”

mentioning

confidence: 99%

Controlled/“Living” Radical Ring-Opening Polymerization of 5,6-Benzo-2-Methylene-1,3-Dioxepane Based on Reversible Addition-Fragmentation Chain Transfer Mechanism

Zou

Pan

2002

Polym J

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ABSTRACT:The radical ring-opening polymerization of 5,6-benzo-2-methylene-1,3-dioxepane (BMDO) was performed in the presence of 1-(ethoxycarbonyl)prop-1-yl-dithiobenzoate (EPDTB) and dicumyl peroxide (DCP). The completely ring-opening polymerization of BMDO via reversible addition-fragmentation transfer mechanism was proved to be controlled by the following experimental evidences: the straight line of ln ([M] 0 /[M] t ) vs. polymerization time; linear increase of molecular weight with increasing conversion and relatively narrow molecular weight distribution. The mechanism of the polymerization was discussed. The complete ring-opened structure of the PBMDO was characterized by 1 H and 13 C NMR spectroscopies as well as gel permeation chromatography (GPC). KEY WORDS Controlled Polymerization / Radical Ring-Opening Polymerization / Reversible Addition-Fragmentation Chain Transfer (RAFT) / 5,6-Benzo-2-Methylene-1,3-Dioxepane / Free radical ring-opening polymerization has been an attractive subject because it produces polymers with various functional groups (such as ethers, esters, amides, and carbonates) in their backbone. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Addition of unsaturated heterocycles into polymerization system of commercial monomers will improve the properties of the polymers obtained. For example, when 2-methylene-4-n-decyl-1,3-dioxolane was copolymerized with vinyl chloride, the thermal stability and flexibility of the polymer obtained improved. 15 However, free radical ring-opening polymerization of the unsaturated heterocycles yields polymers with low molecular weight and broad molecular weight distribution. For instance, the radical ring-opening polymerization of 2-methylene-4-phenyl-1,3-dioxolane proceeds via chain radicals 1 and 2 as shown in Scheme 1. [16][17][18] The chain radicals 1 and 2 are stabilized respectively by two oxygens and phenyl group. The former radical is more active than the later one. The low molecular weight polymer with broad polydispersity index may be due to the transfer reaction during the polymerization.Recently, significant progress has been made in the field of living free radical polymerization including nitroxide-mediate stable free radical polymerization (SFRP); 19-23 atom transfer radical polymerization (ATRP); 24-26 and reversible addition-fragmentation transfer (RAFT) process. 27,28 In these polymerizations, there is a fast equilibrium between propagating radiScheme 1. cals and dormant chains, which is prerequisite for the synthesis of controlled polymers. 29 When the methods apply in the polymerization of unsaturated heterocycles, the termination of propagating radicals must be affected. To produce polymers with controlled molecular weights and architectures, Wei et al. 30 reported the study on nitroxide-mediated stable free radical polymerization of 2-methylene-1,3-dioxepane, which underwent quantitative ring-opening polymerization to afford a polyester with polydispersity less than 1.5. Jia et al. 31 presented the first example of a controlled free r...

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Mechanistic Aspects of Nitroxide-Mediated Controlled Radical Polymerization of Styrene in Miniemulsion, Using a Water-Soluble Radical Initiator

Cited by 117 publications

References 42 publications

Mathematical Modeling of NMRP of Styrene–Divinylbenzene over the Pre‐ and Post‐Gelation Periods Including Cyclization

Mathematical Modeling of NMRP of Styrene–Divinylbenzene over the Pre‐ and Post‐Gelation Periods Including Cyclization

Interfacial Mass Transfer in Nitroxide-Mediated Miniemulsion Polymerization

Controlled/“Living” Radical Ring-Opening Polymerization of 5,6-Benzo-2-Methylene-1,3-Dioxepane Based on Reversible Addition-Fragmentation Chain Transfer Mechanism

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