Micro‐ and Frontal Thermal Field‐Flow Fractionation: On the Shear Degradation of Ultra‐high Molar Mass Polymers

Abstract

Thermal field‐flow fractionation (TFFF) of ultra‐high molar mass (UHMM) polymers revealed that shear degradation of the macromolecules can appear during the fractionation. Since this problem was not resolved adequately and the conflicting results were published previously, it was useful to analyse in detail the published results, and to complement them by the measurements carried out by newly developed micro‐TFFF in order to find the origin of the previous contradictions. Frontal TFFF performed in standard size channels confirmed definitely that shear degradation of polymer chains was not detectable under the investigated experimental conditions.

Keywords:

• Frontal thermal field‐flow fractionation
• Micro‐thermal field‐flow fractionation
• Ultra‐high molar mass polymers
• Shear degradation