Fundamental Aspects of Measuring Copolymerization Reactivity Ratios Using Real‐Time FTIR Monitoring

Puskás, Judit E.; McAuley, Kimberley B.; Chan, Sam W. P.

doi:10.1002/masy.200651105

Cited by 11 publications

(10 citation statements)

References 16 publications

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“…By dividing both k p values the apparent reactivity ratios ( r app ) for both monomers are calculated (Table ) . For copolymerizations of MestOx and C3MestOx with EtOx and nPropOx, changing the polymerization temperatures (140 and 80 °C) did not influence the r app and, thus, the monomer distribution of the resulting polymer is independent of the temperature.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of poly(2‐oxazoline)s with side chain methyl ester functionalities: Detailed understanding of living copolymerization behavior of methyl ester containing monomers with 2‐alkyl‐2‐oxazolines

Bouten

Hertsen

Vergaelen

et al. 2015

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

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Poly(2-oxazoline)s with methyl ester functionalized side chains are interesting as they can undergo a direct amidation reaction or can be hydrolyzed to the carboxylic acid, making them versatile functional polymers for conjugation. In this work, detailed studies on the homo-and copolymerization kinetics of two methyl ester functionalized 2-oxazoline monomers with 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, and 2-npropyl-2-oxazoline are reported. The homopolymerization of the methyl ester functionalized monomers is found to be faster compared to the alkyl monomers, while copolymerization unexpectedly reveals that the methyl ester containing monomers significantly accelerate the polymerization. A computational study confirms that methyl ester groups increase the electrophilicity of the living chain end, even if they are not directly attached to the terminal residue. Moreover, the electrophilicity of the living chain end is found to be more important than the nucleophilicity of the monomer in determining the rate of propagation. However, the monomer nucleophilicity can be correlated with the different rates of incorporation when two monomers compete for the same chain end, that is, in copolymerizations.

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Section: Resultsmentioning

confidence: 99%

Synthesis of poly(2‐oxazoline)s with side chain methyl ester functionalities: Detailed understanding of living copolymerization behavior of methyl ester containing monomers with 2‐alkyl‐2‐oxazolines

Bouten

Hertsen

Vergaelen

et al. 2015

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

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“…The competing, sequence‐controlled (ionic) copolymerization of several monomers to high molecular (multi)block copolymers is rarely reported. Simultaneous copolymerization of different monomers by anionic polymerization is difficult, as in most cases control over monomer incorporation is lost, mainly due to the different nucleophilicities of the propagating species and had only limited success; the terpolymerization of styrene with diphenylethylene (DPE) derivatives was reported to exhibit sequence‐controlled behavior by tuning of the DPE reactivity …”

mentioning

confidence: 99%

“…To date only very few reports use in situ techniques to follow the individual monomer incorporation rates during co‐polymerizations. Infrared or UV spectroscopy was applied to monitor cationic polymerizations at low temperatures and the copolymerization of styrene and isoprene . Real‐time 1 H and/or 13 C nuclear magnetic resonance (NMR) spectroscopy was used for the anionic copolymerization of oxiranes and styrenes …”

mentioning

confidence: 99%

“…molecular (multi)block copolymers is rarely reported. Simultaneous copolymerization of different monomers by anionic polymerization is diffi cult, as in most cases control over monomer incorporation is lost, mainly due to the different nucleophilicities of the propagating species [ 11 ] and had only limited success; [ 7,[12][13][14][15][16][17] the terpolymerization of styrene with diphenylethylene (DPE) derivatives was reported to exhibit sequence-controlled behavior by tuning of the DPE reactivity. [ 18 ] Herein, the simultaneous, sequence-controlled copolymerization of up to fi ve different N -sulfonyl-aziridines, 1 -5 (Figure 1 ), in a one-step, one-pot reaction is presented, i.e., omitting sequential monomer addition.…”

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confidence: 99%

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Sequence-Controlled Polymers via Simultaneous Living Anionic Copolymerization of Competing Monomers

Rieger

Alkan

Manhart

et al. 2016

Macromol. Rapid Commun.

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Natural macromolecules, i.e., sequence-controlled polymers, build the basis for life. In synthetic macromolecular chemistry, reliable tools for the formation of sequence-controlled macromolecules are rare. A robust and efficient chain-growth approach based on the simultaneous living anionic polymerization of sulfonamide-activated aziridines for sequence control of up to five competing monomers resulting in gradient copolymers is presented. The simultaneous azaanionic copolymerization is monitored by real-time (1) H NMR spectroscopy for each monomer at any time during the reaction. The monomer sequence can be adjusted by the monomer reactivity, depending on the electron-withdrawing effect by the sulfonamide (nosyl-, brosyl-, tosyl-, mesyl-, busyl) groups. This method offers unique opportunities for sequence control by competing copolymerization: a step forward to well-engineered synthetic polymers with defined microstructures.

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“…The Meyer-Lowry (M-L) model and its linear variants, such as Finemann-Ross model [11] carry inherent errors, for example, simple re-indexing (M 1 to M 2 and vice versa) may lead to different r 1 and r 2 values. Despite the development of nonlinear methods [13], chemists still continue to use linear methods [14]. Also, in order to apply all these models, data from an actual copolymerization experiment satisfying multiple constraints are required before the reactivity ratios could be determined.…”

Section: Introductionmentioning

confidence: 99%

Prediction of Reactivity Ratios in Free Radical Copolymerization from Monomer Resonance–Polarity (Q–e) Parameters: Genetic Programming-Based Models

Shrinivas¹,

Kulkarni

Shaikh

et al. 2015

International Journal of Chemical Reactor Engineering

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The principal deficiency of the widely utilized Alfrey-Price (AP) scheme for computing reactivity ratios in the widely used free radical copolymerization is that it ignores important factors, such as the steric effects. This often leads to inaccurate reactivity ratio predictions by AP model. Accordingly, in this study, exclusively data-driven, Q-e parameter-based new models have been developed for the reactivity ratio prediction in free radical copolymerization. In the model development, a novel artificial intelligence formalism known as "genetic programming (GP)" that performs symbolic regression has been employed. The GPbased models possess a different functional form than AP model. Further, parameters of GP-based models were finetuned using Levenberg-Marquardt (LM) nonlinear regression method. A comparison of AP, GP and GP-LM as well as artificial neural network (ANN)-based models indicates that GP and GP-LM models exhibit superior reactivity ratio prediction accuracy and generalization performance (with correlation coefficient magnitudes close to or greater than 0.9) when compared with AP and ANN models. The GPbased reactivity ratio prediction models developed here due to their higher accuracy and generalization capability have the potential of replacing the widely used AP models.

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Fundamental Aspects of Measuring Copolymerization Reactivity Ratios Using Real‐Time FTIR Monitoring

Cited by 11 publications

References 16 publications

Synthesis of poly(2‐oxazoline)s with side chain methyl ester functionalities: Detailed understanding of living copolymerization behavior of methyl ester containing monomers with 2‐alkyl‐2‐oxazolines

Synthesis of poly(2‐oxazoline)s with side chain methyl ester functionalities: Detailed understanding of living copolymerization behavior of methyl ester containing monomers with 2‐alkyl‐2‐oxazolines

Sequence-Controlled Polymers via Simultaneous Living Anionic Copolymerization of Competing Monomers

Prediction of Reactivity Ratios in Free Radical Copolymerization from Monomer Resonance–Polarity (Q–e) Parameters: Genetic Programming-Based Models

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