2-SITE MODEL ANALYSIS OF C-13 NMR OF POLYPROPYLENE POLYMERIZED BY ZIEGLER-NATTA CATALYST WITH EXTERNAL ALKOXYSILANE DONORS

Authors
CHUJO R KOGURE Y VAANANEN T
Citation
R. Chujo et al., 2-SITE MODEL ANALYSIS OF C-13 NMR OF POLYPROPYLENE POLYMERIZED BY ZIEGLER-NATTA CATALYST WITH EXTERNAL ALKOXYSILANE DONORS, Polymer, 35(2), 1994, pp. 339-342
Citations number
23
Categorie Soggetti
Polymer Sciences
Journal title
Polymer → ACNP
ISSN journal
00323861
Volume
35
Issue
2
Year of publication
1994
Pages
339 - 342
Database
ISI
SICI code
0032-3861(1994)35:2<339:2MAOCN>2.0.ZU;2-#
Abstract
Two-site model analysis was carried out for C-13 n.m.r. of polypropyle ne polymerized by Ziegler-Natta catalyst with external alkoxysilane do nors. Four effects of the external donors were found: selective poison ing 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 isotacticit y of the polymers obtained by the fluctuating site when the concentrat ion of external donor is high enough.