Fractionation of Polymers

Abstract

Synthetic and natural polymers exist in microstructural distributions, such as chain length, size, chemical composition, branching, tacticity, or comonomer sequence distributions. Polymer fractionation techniques are essential for the analysis of these distributions and help in understanding polymerization mechanisms and material properties. In this article, the theoretical basics of general fractionation approaches and specific fractionation techniques are discussed. Details are given on fractionation techniques for molar mass and chemical composition distribution analysis, such as temperature rising elution fractionation (TREF), crystallization analysis fractionation (CRYSTAF), or crystallization elution fractionation (CEF). In addition, column‐based and channel‐based fractionation methods are extensively discussed. Theoretical and practical aspects of the analysis of molar mass distributions using size exclusion chromatography (SEC) as well as chemical composition distributions by interaction chromatography (SGIC, TGIC, LCCC) and multidimensional separations (2D‐LC) are reviewed and compared. General aspects and details on asymmetrical flow and thermal field flow fractionation techniques (AF4 and ThFFF) are discussed and examples of suitable physical and chemical detectors coupled to fractionation devices for the analysis of size, conformation, or chemical composition and topology are demonstrated.