Simultaneous Deconvolution of the Bivariate Molecular Weight and Chemical Composition Distribution of Ethylene/1-Hexene Copolymers

The bivariate molecular weight and chemical composition distribution (MWDxCCD) of ethylene/1-hexene copolymers can be measured using TREFxGPC cross fractionation characterization (CFC). In this work, the experimental MWDxCCD of ethylene/1-hexene copolymers made with a Ziegler-Natta catalyst under different polymerization conditions are measured by CFC and deconvoluted to identify the minimum number of site types present in the catalyst. Blends of ethylene/1-hexene copolymers produced with a metallocene catalyst with known MWDxCCD are used to validate the proposed technique. This is a powerful methodology to better understand the nature of active sites on multisite catalysts, and can be beneficial for the development of copolymers with precisely controlled microstructures.