SEC Gradients: An Alternative Approach to Polymer Gradient Chromatography. Separation of Poly(methyl methacrylate-stat-methacrylic acid) by Chemical Composition

Abstract

The development of a chromatographic method capable to separate poly(methyl methacrylate-stat-methacrylic acid) samples with methacrylic acid contents of up to 50% by chemical composition is described. For this purpose a gradient ranging from chloroform to dimethylacetamide on a PSS PROTEEMA column was applied. The application of a conventional gradient resulted in severe breakthrough peaks. Therefore, the recently developed concept of SEC gradients was used. No breakthrough peaks were observed, and the peaks corresponding to samples of different content of methacrylic acid were well resolved. A nearly linear relationship between elution volume and methacrylic acid content was observed. The developed method allows determination of the chemical composition distribution of the abovementioned class of polymers.

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

“…However, despite the wide spread use of such materials, information on the chemical composition distribution of such materials is scarce, although application properties, e.g., solubility is heavily dependent on acid content and therefore the speed of dissolution will be influenced by the CCD. We have recently reported on the separation of poly(methyl methacrylate‐ stat ‐methacrylic acid) having acid contents between 0% and 50% according to methacrylic acid content . The present paper extends the work to the separation of poly( n ‐butyl acrylate‐ stat ‐acrylic acid)s with acrylic acid contents ranging from 0% to 100%.…”

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

“…To monitor and improve the industrial processes as well as improving end-product properties, there is a need for characterization of the acid incorporation in polymers, as is it responsible for the stabilization of the polymer particles. Analysis of the average-acid content in copolymers can be performed with titration [1] , nuclear-magnetic-resonance (NMR) spectroscopy, liquidchromatographic (LC) separation techniques in either reversedor normal-phase modes [2][3][4][5][6][7] and gradient-size-exclusion chromatography (gradient-SEC) [8][9][10][11] . Although the described separation methodologies have a broad application window, specifically for copolymers, the currently available separation methodologies yield no direct correlation between retention behaviour and presence or distribution of acid groups for samples with compositional differences, because retention also depends on the overall polymer polarity.…”