Charge-based separation of synthetic macromolecules by non-aqueous ion exchange chromatography

Brooijmans, Ton; Breuer, Pascal; Schoenmakers, Peter J.; Peters, Ron

doi:10.1016/j.chroma.2020.461351

Cited by 8 publications

(11 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…applying this detector demonstrated a linear response after correction as described by Boborodea et al. and similar response functions for a variety of polymers, as can be seen in Figure 3 [69].…”

Section: Detectors In Polymer Lc and Their Strengths And Weaknessessupporting

confidence: 61%

See 1 more Smart Citation

Detection challenges in quantitative polymer analysis by liquid chromatography

Knol

Pirok

Peters

2020

J of Separation Science

View full text Add to dashboard Cite

Accurate quantification of polymer distributions is one of the main challenges in polymer analysis by liquid chromatography. The response of contemporary detectors is typically influenced by compositional features such as molecular weight, chain composition, end groups, and branching. This renders the accurate quantification of complex polymers of which there are no standards available, extremely challenging. Moreover, any (programmed) change in mobile‐phase composition may further limit the applicability of detection techniques. Current methods often rely on refractive index detection, which is not accurate when dealing with complex samples as the refractive‐index increment is often unknown. We review current and emerging detection methods in liquid chromatography with the aim of identifying detectors, which can be applied to the quantitative analysis of complex polymers.

show abstract

Section: Detectors In Polymer Lc and Their Strengths And Weaknessessupporting

confidence: 61%

“…showing a linear relation after correction and similar response functions for a variety of polymer samples of different molecular weight distributions. Reprinted from [69], copyright 2020, with permission from Elsevier…”

Section: Detectors In Polymer Lc and Their Strengths And Weaknessesmentioning

confidence: 99%

Detection challenges in quantitative polymer analysis by liquid chromatography

Knol

Pirok

Peters

2020

J of Separation Science

View full text Add to dashboard Cite

show abstract

“…Heteroconjugation conditions were achieved by using 20 mM TMG in NMP with 40 mM (formic, acetic, propionic, benzoic, hexanoic, lauric, and oleic) acids as a background electrolyte. The essentially neutral polymers are intended to be charged by the laurate anion, which is obtained from deprotonation by TMG. Analysis is performed using a 500 mm capillary with 75 μm i.d., with hydrodynamic injection (10 s, 25 mbar), 30 kV voltage, 60 °C cassette temperature, and 25 mbar positive pressure applied on the sample inlet during analysis.…”

Section: Experimental Sectionmentioning

confidence: 99%

“…To monitor and improve industrial processes as well as to improve end-product properties, there is a strong need for methods allowing characterization of acid incorporation in polymers. Recently, a non-aqueous ion-exchange chromatography approach was developed, which could selectively separate polymers according to the content of incorporated carboxylic acid …”

Section: Introductionmentioning

confidence: 99%

“…, performing NACE). Previous research revealed that N -methyl-2-pyrrolidone (NMP) is a good solvent for both the acid-functional polymers under study and the solubility of bases used for their deprotonation. However, under non-aqueous conditions, the p K a of acids shifts to significantly higher values. − As a result, most organic bases do not have the base strength to dissociate these acids under non-aqueous conditions.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Charge-Based Separation of Acid-Functional Polymers by Non-aqueous Capillary Electrophoresis Employing Deprotonation and Heteroconjugation Approaches

et al. 2021

Self Cite

View full text Add to dashboard Cite

Water-borne polymers are in ever-increasing demand due to their favorable ecological profile compared to traditional solvent-borne polymer systems. Many water-borne polymer particles are stabilized in aqueous media by the incorporation of acid-functional monomers. Due to the large variety of comonomers applied, these water-borne polymers have various superimposed statistical distributions, which make it challenging to obtain in-depth information regarding incorporation of the acidic monomers. For selective analysis of the incorporated acidic monomers, a charge-based non-aqueous capillary electrophoresis (NACE) separation was developed. Two approaches were developed: (i) deprotonation of the acid functionality with an organically soluble strong base and (ii) heteroconjugation of anions of carboxylic acids with incorporated acid functionality. In both approaches, N-methylpyrrolidone, as a strong solvent for polymers with a favorable relative permittivity for the presence of dissociated ionic species, was used for the separation. It was shown that anions of carboxylic acids specifically associate with the incorporated acid groups in the polymers, resulting in negatively charged complexes that could be separated based on charge-to-size ratio by NACE. Although both approaches give comparable results with respect to acid distribution for acid-functional polymers, the effective mobility of the deprotonated polymers is roughly double that obtained from the heteroconjugation approach. Unlike the heteroconjugation approach, deprotonation conditions were detrimental to the fused-silica capillary, limiting practical use. Polymers with different chemical compositions, molecular weights, and acid contents were subjected to the CE approaches developed. Polymers with varying molecular weight but similar relative acid monomer content were shown to have similar migration times, which confirms that this approach separates polymers based on charge-to-size ratio.

show abstract