UniSa - IRIS Institutional Research Information System
IRIS è la soluzione IT che facilita la raccolta e la gestione dei dati relativi alle attività e ai prodotti della ricerca. Fornisce a ricercatori, amministratori e valutatori gli strumenti per monitorare i risultati della ricerca, aumentarne la visibilità e allocare in modo efficace le risorse disponibili.
EnglishPolymer microstructures obtained by copolymerizations of (Z)-1,3-pentadiene with ethene, conducted at different temperatures by the CpTiCl3-MAO catalytic system, have been characterized by detailed 13C NMR analyses. The observed microstructures indicate an essential role of the backbiting of the allyl-terminated growing chain on the occurrence of 1,2 syndiotactic and 1,4-cis high selectivities, which are observed for (Z)-1,3-pentadiene homopolymerizations at low and high temperatures, respectively. Molecular modeling studies suggest that the occurrence of 1,2-syndio and 1,4-cis stereoselectivities would be determined by the steric constrain (and stereorigidity) associated with the maintenance, in monomer bound intermediates, of the backbiting coordination of syn and anti allyl-terminated growing chains, respectively.
| Titolo: | High selectivity in polymerization of (Z)-1,3-pentadiene, with the CpTiCl3-MAO catalytic system, generated by backbiting coordinations of the growing polydienyl chain. |
| Autori: | |
| Data di pubblicazione: | 2004 |
| Rivista: | |
| Abstract: | Polymer microstructures obtained by copolymerizations of (Z)-1,3-pentadiene with ethene, conducted at different temperatures by the CpTiCl3-MAO catalytic system, have been characterized by detailed 13C NMR analyses. The observed microstructures indicate an essential role of the backbiting of the allyl-terminated growing chain on the occurrence of 1,2 syndiotactic and 1,4-cis high selectivities, which are observed for (Z)-1,3-pentadiene homopolymerizations at low and high temperatures, respectively. Molecular modeling studies suggest that the occurrence of 1,2-syndio and 1,4-cis stereoselectivities would be determined by the steric constrain (and stereorigidity) associated with the maintenance, in monomer bound intermediates, of the backbiting coordination of syn and anti allyl-terminated growing chains, respectively. |
| Handle: | http://hdl.handle.net/11386/1059747 |
| Appare nelle tipologie: | 1.1.2 Articolo su rivista con ISSN |
File in questo prodotto:
http://hdl.handle.net/11386/1059747
Copyright © 2020