Asymmetrical flow field-flow fractionation (AF4) is rapidly becoming a technique of choice for the separation and characterization of complex materials. It is capable of fractionating samples over a wide size (from a few nanometers to micrometers in diameter) and molecular weight range (10<sup>3</sup>–10<sup>10</sup> g/mol). It offers gentle, low shear, low pressure separation conditions. These conditions are essential to ultra large polymer characterization because the size fractionation upper limit is extended, and the polymer chain deformation and degradation can be minimized compared to the most commonly practiced size exclusion chromatography technique. Alkali soluble acrylic polymer dispersions are an industrially important class of polymers used as thickeners in multiple applications. A set of these dispersions with systematic molecular weight changes was made using the Large Volume Semi-Continuous Parallel Pressure Reactor (LV-ScPPR) which is an automated system designed for running emulsion polymerizations. These polymers were analyzed via AF4 with on-line multi-angle light scattering, and the results will be discussed. Complementary characterization techniques including Gel Permeation Chromatography of the polymer backbone after hydrolysis of the acrylic ester groups, solubilized viscosity, and gel fraction were also used to characterize the polymers, and these results will be presented for comparison.

Characterization of acrylic alkali soluble polymer dispersions by asymmetrical flow field-flow fractionation

255th National Meeting (2018)

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