Effect of medium pH on the reactivity ratios in acrylamide acrylic acid copolymerization

Parıl, Ahmet; Alb, Alina M.; Giz, Ahmet; Çatalgil‐Giz, Huceste

doi:10.1002/app.25271

Cited by 23 publications

(32 citation statements)

References 24 publications

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“…As discussed in the introduction, there are no reports for the reactivity ratios of this comonomer system calculated in aqueous phase at fully ionized conditions of the MAA monomer. However, reactivity ratios of AA and AM in aqueous phase at fully ionized conditions have been investigated by several groups [8,[43][44][45][46]. Preusser et al have done an extensive experimental analysis including copolymerization in a broad range of initial monomer concentrations and degrees of ionization and have determined the reactivity ratios.…”

Section: Maa-co-pegma5 (5 Ethylene Glycol Units)mentioning

confidence: 99%

Kinetics of the Aqueous-Phase Copolymerization of MAA and PEGMA Macromonomer: Influence of Monomer Concentration and Side Chain Length of PEGMA

et al. 2017

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An in situ nuclear magnetic resonance spectroscopy (NMR) technique is used to monitor the aqueous-phase copolymerization kinetics of methacrylic acid (MAA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers. In particular, the study analyses the effect of the number of ethylene glycol (EG) groups along the lateral chains of PEGMA and is carried out under fully ionized conditions of MAA at different initial monomer ratios and initial overall monomer concentrations (5-20 wt % in aqueous solution). The composition drift with conversion indicates that PEGMA macromonomer is more reactive than MAA. Individual monomer consumption rates show that the rates of consumption of both monomers are not first order with respect to overall concentration of the monomer. The reactivity ratios estimated from the copolymerization kinetics reveal, that for the short PEGMA, the reactivity ratios r MAA and r PEGMA increase with the solids content (SC). A totally different trend is obtained for the longer PEGMA, whose reactivity ratio (r PEGMA23 ) decreases with solids content, whereas the reactivity ratio of MAA remains roughly constant.

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Section: Maa-co-pegma5 (5 Ethylene Glycol Units)mentioning

confidence: 99%

Kinetics of the Aqueous-Phase Copolymerization of MAA and PEGMA Macromonomer: Influence of Monomer Concentration and Side Chain Length of PEGMA

et al. 2017

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“…However the reactivity ratios of charged monomers depend strongly on the pH and less strongly on the total ionic strength of the solution. [20,39,40] In general, the reactivity of a monomer decreases as it becomes ionized. This behavior can be understood as a result of the electrostatic repulsion between the ionic monomer and the charged polymer coil.…”

Section: Resultsmentioning

confidence: 99%

“…[12][13][14][15][16][17][18] Copolymerization of styrene with methyl methacrylate and Aam with acrylic acid were monitored and the reaction parameters were obtained from online data. [19][20] ACOMP technique allows data to be obtained continuously during the reaction. In on-line techniques a large amount of data are obtained for each experiment resulting in more accurate determination of reaction parameters.…”

Section: Introductionmentioning

confidence: 99%

Online Monitoring of 4‐Vinylbenzene sulfonic acid Sodium Salt – Acrylamide Copolymerization in Water

Parıl

Alb

Giz

et al. 2009

Macromolecular Symposia

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Summary: 4-Vinylbenzene sulfonic acid sodium salt (VB) -Acrylamide (Aam) homopolymerization and copolymerization reactions with various feed ratios were performed in water at 60 8C. All reactions were monitored online, by an Automatic Continuous Online Monitoring of Polymerization (ACOMP) system. The concentrations of the two comonomers in their monomeric form, as well as their concentrations incorporated into polymer, were obtained from the monitored data. It was seen that Aam homopolymerization was faster than VB and both homopolymerization rates were higher than copolymerization rates at any combination. In the reactions with 1.5%, 5% and 10% (mol) VB, VB was completely depleted and further reaction was Aam homopolymerization. In the copolymerizations with 5 to 50% initial VB content, the plots of VB fraction in the remaining monomer mixture versus conversion exhibited a corner at 10-30% conversion. This corner showed that the behavior of the reaction changed abruptly at this point. In the first stage of the reactions, the composition was seen to be almost constant with almost no composition drift whereas in the second part, the VB fraction decreased monotonically. Monomer reactivity ratios (MRR) were calculated by error in variables (EVM) method. Since the reactions gave two distinguishable regions, the reaction part before and after the corner were evaluated separately. Therefore, the monomer reactivity ratios were found as r Aam ¼ 0.34 AE 0.07, r VB ¼ 0.40 AE 0.21 for the part before and r Aam ¼ 0.2 AE 0.04, r VB ¼ 9.0 AE 0.8 for the part after the corner.

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“…The nature and extent of such interactions are determined primarily by the electrostatic properties of the repeating units in the chains, namely the number, sign, and displacement of the monomer charges. In this context, the linear charge density of the polymer is a relevant parameter to correlate the monomer charge properties and the chain composition with the electrostatic features of polyelectrolytes [8,9].…”

Section: Introductionmentioning

confidence: 99%

Effect of the charge interactions on the composition behavior of acrylamide/acrylic acid copolymerization in aqueous medium

Fischer

Cuccato

Storti

et al. 2018

European Polymer Journal

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Acrylamide and sodium acrylate are copolymerized in aqueous solution to study the influence of monomer concentration and ionic strength onto the reactivity ratios using in-situ 1 H NMR. Increasing the monomer content leads to larger reactivity of the ionized monomer. At low monomer concentration, this effect was reproduced by adding NaCl to increase the ionic strength, indicating that the reaction kinetics is largely governed by charge interactions. On the contrary, this was not observed at higher monomer content, suggesting that non-electrostatic effects are mainly responsible of the monomer concentration dependence at these conditions. A comprehensive mathematical model was developed to predict copolymer composition as a function of monomer concentration and ionic strength. It is based on a previously-proposed rate law of propagation for ionized monomers, which has been expanded to cover any ionization degree of acrylic acid. The model is capable to reproduce composition data from different sources obtained in a wide range of reaction conditions.

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Effect of medium pH on the reactivity ratios in acrylamide acrylic acid copolymerization

Cited by 23 publications

References 24 publications

Kinetics of the Aqueous-Phase Copolymerization of MAA and PEGMA Macromonomer: Influence of Monomer Concentration and Side Chain Length of PEGMA

Kinetics of the Aqueous-Phase Copolymerization of MAA and PEGMA Macromonomer: Influence of Monomer Concentration and Side Chain Length of PEGMA

Online Monitoring of 4‐Vinylbenzene sulfonic acid Sodium Salt – Acrylamide Copolymerization in Water

Effect of the charge interactions on the composition behavior of acrylamide/acrylic acid copolymerization in aqueous medium

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