Front Cover: The cover shows the superposition of ethylene polymerization rates with a Ziegler‐Natta catalyst at 4 different polymerization times. At the end of each polymerization, we measured the molecular weight distribution (MWD) and average short chain branching frequency (SCB) across the MWD using gel permeation chromatography with an online infrared detector. Deconvolution of this microstructural data using the equations shown in the figure permits the determination of average molecular weights and SCB frequencies per site type for these catalysts. Further details can be found in the article by João Soares and co‐workers on page 206.
This article proposes a method to quantify the polymerization kinetics of ethylene and α-olefins with commercial TiCl 4 /MgCl 2 Ziegler-Natta catalysts. The method determines the leading apparent polymerization kinetic constants for each active site in a Ziegler-Natta catalyst by simultaneously fitting the instantaneous polymerization rate, cumulative polymer yield, and polymer molecular weight distribution measured at different times during a series of semi-batch polymerization experiments. This approach quantifies the behavior of olefin polymerization with multisite catalysts using the least number of adjustable parameters needed to consistently model polymerization kinetics and polymer microstructural data.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.