Describing and quantifying the chemical composition distribution in unimodal and multimodal ZN-polyethylene using CRYSTAF

摘要

A new approach in describing and quantifying the chemical composition distribution (CCD) in Ziegler-Natta-polyethylene copolymers was developed by using crystallization analysis fractionation (Crystaf). Copolymers of ethylene and alpha-olefins (1-butene and 1-hexene) polymerized with different ZN catalyst systems were analyzed. Distinct differences in the CCD between the different polymer types (catalyst-cocatalyst system and comonomer type) were observed and could be quantified. Same approach was applied to 2-dimensional fractionation technique, cross fractionation chromatography, to describe and quantify the CCD of multimodal polyethylene copolymers. (C) 2015 Wiley Periodicals, Inc.