Two-site model analysis of 13C n.m.r. of polypropylene polymerized by Ziegler-Natta catalyst with external alkoxysilane donors

Autor:	Riichirô Chûjô, Taito Väänänen, Y. Kogure
Rok vydání:	1994
Předmět:	chemistry.chemical_classification Polypropylene Polymers and Plastics Organic Chemistry Concentration effect Polymer Catalysis chemistry.chemical_compound Stereospecificity chemistry Polymerization Polymer chemistry Materials Chemistry Lewis acids and bases Ziegler–Natta catalyst
Zdroj:	Polymer. 35:339-342
ISSN:	0032-3861
DOI:	10.1016/0032-3861(94)90700-5
Popis:	Two-site model analysis was carried out for 13 C n.m.r. of polypropylene polymerized by Ziegler-Natta catalyst with external alkoxysilane donors. Four effects of the external donors were found: selective poisoning of symmetric site; transformation of a symmetric to an asymmetric (but fluctuating) site; increase of whole isotacticity due to that of polymers obtained by the fluctuating site; and increase of isotacticity of the polymers obtained by the fluctuating site when the concentration of external donor is high enough.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::0426578cab088ebd2845e26658f367bf https://doi.org/10.1016/0032-3861(94)90700-5 Zobrazit plný text záznamu