User Tools

    To create and edit articles, please register and log-in

Main Menu

Main menu
Click categories to expand


A-Z listingplugin-autotooltip__plain plugin-autotooltip_bigA-Z listing

This is an alphabetical index of all content pages.


Other categories

Utilities

Contact
Register

Also see

Importance Ratings
News
Legal
Donate/Sponsor
Curator's rationale


Wikenigma supports:


Feeds etc
rss / xml feed
sitemap file
A-Z listing (archived)


Auto-Translate Site
Indexed under : Chemistry

Wikenigma - an Encyclopedia of Unknowns Wikenigma - an Encyclopedia of the Unknown

Ziegler-Natta catalysts

The Heterogeneous Ziegler-Natta (ZN) catalytic process was discovered in the 1950s and is still a fundamental part of the manufacture of many plastics - e.g. polyethylene (polythene) and polypropylene. Earning the creators the 1963 Nobel Prize for Chemistry.

The process is part of a group of reactions called Coordination Polymerizations, and typically uses titanium tetrachloride (TiCl4) and an organo-aluminium co-catalyst based on trialkyl-aluminium complexes. Sometimes magnesium chloride (MgCl2) is also used.

Because of its commercial significance, the nature of the active catalytic centre(s) has been of intense research, but has not yet been clarified.

Despite of the relevance of ZN catalysts for the large-scale production of polyolefins, a clear mechanistic understanding of these catalysts is still incomplete due to the elusive nature of the active site structures. Over the last two decades, researchers have used density functional theory (DFT) methods to clarify the polymerization mechanisms and to identify the nature of the active sites, unraveling the influence of supports, cocatalysts, and the effect of internal and external donors on the polymerization processes.

Source : Progress in Polymer Science , Volume 84, Pages 89-114


    Share this page :

Dear reader : Do you have any suggestions for the site's content?

Ideas for new topics, and suggested additions / corrections for old ones, are always welcome.

If you have skills or interests in a particular field, and have suggestions for Wikenigma, get in touch !


Or, if you'd like to become a regular contributor . . . request a login password. Registered users can edit the entire content of the site, and also create new pages.

( The 'Notes for contributors' section in the main menu has further information and guidelines etc.)

Automatic Translation

You are currently viewing an auto-translated version of Wikenigma

Please be aware that no automatic translation engines are 100% accurate, and so the auto-translated content will very probably feature errors and omissions.

Nevertheless, Wikenigma hopes that the translated content will help to attract a wider global audience.

Show another (random) article

DOKUWIKI IMPLEMENTATION DESIGN BY UNIV.ORG.UK MAY 2022