Size-exclusion chromatography (SEC) and asymmetric flow field-flow fractionation (AF4) are widely used techniques for separation and characterization of the molecular weight distributions (MWD) and molecular architecture of polymers. However, synthetic polymers are complex mixtures, often containing functional groups that may self-associate under typical SEC conditions. Under such circumstances, it is a challenge to obtain reliable molecular weight distribution data. In this talk, strategies to defeat both hydrophobic and hydrophilic self-association during SEC analysis will be presented. Techniques for assessment of self-association and its impact on the ideality of the SEC conditions elution will also be discussed. Additionally, the characterization of branched polymers can be challenging by SEC as anomalous late elution is often observed for these types of materials. As such the obtained MWD data and conformation plots are not reliable for elucidation of molecular architecture and branch index. In this talk, AF4 and SEC will be compared and contrasted to show the relative advantages and disadvantages of these two techniques (Figure 1) for the characterization of branched polymers.

Advanced size-exclusion chromatography and field-flow fractionation for characterization of complex synthetic polymers

2019 Fall National Meeting

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