title: Improved SEC-FTIR method for the characterization of multimodal high-density polyethylenes.
abstract: A size-exclusion chromatography-Fourier transform infrared spectroscopy (SEC-FTIR) method for the analysis of high-density polyethylene copolymers was developed, providing superior resolution for the determination of short-chain branching as a function of time and improved repeatability by hardware adaptation and processing optimization. SEC-FTIR for characterization of polyolefins is a compromising technique. Best resolution in terms of molecular weight and molecular weight distribution requires a very low sample solution concentration in size-exclusion chromatography while best results from online infrared (IR) spectroscopy require as high concentrations as possible. The signal-to-noise ratio at the IR detector could be increased significantly after application of a bandpass filter instead of a steel mesh attenuator and furthermore influences of system instabilities could be decreased by changes in data processing. Reliable short-chain branching information in the high molecular weight section in respect to accuracy and repeatability with better chromatographic resolution could be achieved.
authors.affiliation: Borealis Polyolefine GmbH, Linz, Austria. christian.piel@borealisgroup.com
authors.forename: Christian
authors.initials: C
authors.lastname: Piel
authors.forename: Andreas
authors.initials: A
authors.lastname: Albrecht
authors.forename: Corinna
authors.initials: C
authors.lastname: Neubauer
authors.forename: Christian W
authors.initials: CW
authors.lastname: Klampfl
authors.forename: Jens
authors.initials: J
authors.lastname: Reussner
mesh_terms: D002850:Chromatography, Gel; D011095:Polyethylenes / Q000032:analysis*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D011095:Polyethylenes