Phase separation in random copolymers from high conversion free radical copolymerization, 4. Chemical heterogeneity analysis of poly[(methyl methacrylate)‐
            <i>co</i>
            ‐(ethyl acrylate)] and poly[(methylmethacrylate)‐
            <i>co</i>
            ‐(butylacrylate)] by gradient HPLC and the effect on glass transition

Braun, Dietrich; Krämer, Inge; Pasch, Harald

doi:10.1002/1521-3935(20000601)201:10<1048::aid-macp1048>3.0.co;2-#

Cited by 16 publications

(11 citation statements)

References 17 publications

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“…It has been found previously that high-conversion random copolymers can exhibit in situ phase separation [8,10]. The formation of different phases is due to the fact that, when going to high-conversion polymerisation, macromolecules are formed that have For the establishment of the relation between CCD and phase separation it was interesting to monitor the in situ phase separation.…”

Section: Phase Separation Behaviour Of High-conversion Sea Copolymersmentioning

confidence: 97%

“…In the later stages of the copolymerisation, the major part of styrene is consumed and higher amounts of ethyl acrylate are incorporated into the polymer chains. As a result, at higher conversion the polymer chains contain higher amounts of ethyl acrylate [8,10]. This difference in the monomer reactivities leads to a significant chemical heterogeneity of high-conversion copolymers.…”

Section: Chemical Heterogeneity Of High-conversion Sea Copolymersmentioning

confidence: 99%

“…This difference in the monomer reactivities leads to a significant chemical heterogeneity of high-conversion copolymers. For the quantitative analysis of this chemical heterogeneity, gradient HPLC can be used as has been shown previously [3,10]. To fit the requirements of the high-throughput screening, a very short HPLC column was used at high flow rate.…”

Section: Chemical Heterogeneity Of High-conversion Sea Copolymersmentioning

confidence: 99%

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Determination of chemical composition and molar mass distribution of random styrene-ethyl acrylate copolymers by high-throughput liquid chromatography

Romero¹,

Bashir²,

Pasch

2005

E-Polymers

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Synthesis and characterization of random copolymers by spectroscopic and chromatographic techniques are normally slow and expensive because most measurements are conducted consecutively and no high-throughput techniques are used. In the present work parallel synthesis and high-throughput analytical techniques for random styrene-ethyl acrylate copolymers were developed. With combinatorial methods, high-throughput instruments and a better design of experiments, the molar mass and chemical composition analyses were carried out simultaneously with time savings of more than 90% as compared to conventional set-ups. The chemical heterogeneity of high-conversion styrene-ethyl acrylate copolymers was determined successfully by fast gradient HPLC. Determination of the average composition was carried out via selective UV detection in size exclusion chromatography. The results were verified by 1 H NMR and calculations based on the copolymerisation parameters. Differential scanning calorimetry and optical microscopy techniques were used for determination of the phase separation behaviour of the copolymers and correlated with the chemical heterogeneity.

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Section: Phase Separation Behaviour Of High-conversion Sea Copolymersmentioning

confidence: 97%

Section: Chemical Heterogeneity Of High-conversion Sea Copolymersmentioning

confidence: 99%

Section: Chemical Heterogeneity Of High-conversion Sea Copolymersmentioning

confidence: 99%

See 1 more Smart Citation

Determination of chemical composition and molar mass distribution of random styrene-ethyl acrylate copolymers by high-throughput liquid chromatography

Romero¹,

Bashir²,

Pasch

2005

E-Polymers

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show abstract

“…The reason for the lack of information on the CCD as compared with the knowledge on the MMD results from the fact that determination of CCD requires separating the individual copolymer chains by their chemical composition. Such separations are usually performed by gradient chromatography, sometimes termed as gradient elution liquid chromatography (GELC) or solvent gradient interaction chromatography (SGIC) . In a typical gradient experiment, the sample is dissolved in a solvent that allows for adsorption of the analyte molecules to the stationary phase, followed by successive desorption of the sample components by application of a solvent gradient of increasing eluotropic strength.…”

Section: Introductionmentioning

confidence: 99%

Characterization of the Chemical Composition Distribution of Poly(n‐butyl acrylate‐stat‐acrylic acid)s

Maier

Malz

Radke

2014

Macro Chemistry & Physics

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A size exclusion chromatography (SEC)‐gradient method is developed allowing poly(n‐butyl acrylate‐stat‐acrylic acid)s to be separated with respect to content of acrylic acid over the complete composition range. After setting up the chromatographic method, samples that, according to the amounts of charged monomers, are expected to have identical chemical composition are compared. The chromatograms reveal differences in elution volume, which, by 1H NMR spectroscopy, can be partially traced back to differences in polymer composition. In addition, samples of similar compositions prepared in different solvents exhibit differences in chemical composition distribution.

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“…General consideration of the effect of chemical heterogeneity on copolymer properties has so far been limited 15. The chemical heterogeneity of copolymers affects the separation processes, eg in the determination of molecular weights by chromatographic methods16–19 or liquid–liquid phase equilibria used for copolymer fractionation 20, 21. Its impact on the integral properties has not been systematically studied.…”

Section: Introductionmentioning

confidence: 99%

The effect of chemical heterogeneity on the properties of statistical copolymers: the conductivity of poly(aniline‐co‐2‐bromoaniline)

Stejskal

2004

Polymer International

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Chemical heterogeneity can influence the properties of statistical copolymers. It is shown that any integral property of a copolymer will depend on the chemical heterogeneity if such a property is a non‐linear function of copolymer composition. This is illustrated by means of the conductivity of copolymers of aniline and 2‐bromoaniline. The monomer reactivity ratios of this monomer pair are rA (aniline) = 0.94 and rB (2‐bromoaniline) = 0.31. The dependence of conductivity on the copolymer composition is non‐linear. Consequently, the conductivity depends on the compositional distribution, ie on the extent of chemical heterogeneity. Heterogeneous high‐conversion copolymers have lower conductivity than corresponding relatively homogeneous low‐conversion copolymers. The change in the average copolymer composition with increasing conversion is demonstrated for a copolymerization mixture containing 30 mol% aniline. The conductivity decreases at the same time as the chemical heterogeneity of the copolymer develops. The change in the average copolymer composition alone cannot explain the observed conductivity decrease. The conductivity is dependent not only on average composition but also on the chemical composition distribution. Copyright © 2004 Society of Chemical Industry

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Phase separation in random copolymers from high conversion free radical copolymerization, 4. Chemical heterogeneity analysis of poly[(methyl methacrylate)‐ co ‐(ethyl acrylate)] and poly[(methylmethacrylate)‐ co ‐(butylacrylate)] by gradient HPLC and the effect on glass transition

Cited by 16 publications

References 17 publications

Determination of chemical composition and molar mass distribution of random styrene-ethyl acrylate copolymers by high-throughput liquid chromatography

Determination of chemical composition and molar mass distribution of random styrene-ethyl acrylate copolymers by high-throughput liquid chromatography

Characterization of the Chemical Composition Distribution of Poly(n‐butyl acrylate‐stat‐acrylic acid)s

The effect of chemical heterogeneity on the properties of statistical copolymers: the conductivity of poly(aniline‐co‐2‐bromoaniline)

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