Temperature Rising Elution Fractionation × Size Exclusion Chromatography Cross-Fractionation of Ethylene/1-Hexene Copolymers: Model Development and Applications

A mathematical model is presented for the cross fractionation (CFC) of ethylene/1-olefin copolymers by temperature rising elution fractionation (TREF) combined with size exclusion chromatography (SEC). The model demonstrates good agreement with the experimental data. This validated model is applied to investigate how molecular weight, chemical composition, and operating conditions (i.e., cooling rate, heating rate, solvent flow rate, and temperature step size) influence CFC profiles. It predicts the complex interplay between crystallization and hydrodynamic fractionation, providing a quantitative framework for the interpretation and optimization of CFC analyses. This tool enhances the microstructural characterization of the ethylene/1-hexene copolymer and supports the design of materials with tailored properties.