High Temperature Interaction Chromatography of Olefin Copolymers

Summary: The synthesis and characterization of polyolefins continues to be one of the most important areas for academic and industrial polymer research. One consequence of the development of new “tailor-made” polyolefins is the need for new and improved analytical techniques for the analysis of polyolefins with respect to molar mass and chemical composition distribution. The present article briefly reviews different new and relevant chromatographic techniques for polyolefin analysis. For the fast analysis of the chemical composition distribution of polyolefins a new high-temperature gradient high-performance liquid chromatography (HPLC) system has been introduced. The efficiency of this system for the separation of various olefin copolymers is demonstrated. The correlation between elution volume and chemical composition can be accessed by on-line coupling of high temperature HPLC with FTIR spectroscopy. For the elucidation of the chemical composition as a function of molar mass high-temperature size exclusion chromatography and ¹H-NMR spectroscopy can be coupled. It is shown that the on-line NMR analysis of chromatographic fractions yields information on microstructure and chemical composition in addition to molar mass distribution.