Abstract

High‐temperature thermal gradient interaction chromatography (HT‐TGIC) fractionates polyolefins based on an adsorption–desorption mechanism. Several factors influence the shape and position of HT‐TGIC chromatograms, notably polymer microstructure, analytical conditions, and, to a lesser extent, solvent type. This article investigates the joint influence of chain length and comonomer content of a series of polyethylene and ethylene/1‐octene copolymers having similar 1‐octene fractions (0–13 mol%) and a wide range of molecular weights on HT‐TGIC fractionation. For each series of copolymers having similar 1‐octene fraction, the elution peak temperature decreases exponentially and the profiles become increasingly broader below a critical number average chain length value. The authors use Monte Carlo simulation and Stockmayer distribution to explain the observed behavior, finding that no simple correlation exists between ethylene sequences in the copolymers and peak elution temperature, but that there is strong evidence that axial dispersion is responsible for symmetrical broadening of the HT‐TGIC profiles. The authors also study the HT‐TGIC of binary blends, finding that components with similar 1‐octene contents and dissimilar chain lengths tend to increase co‐adsorption/co‐desorption effects. image

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.