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Simultaneous Chain-Growth and Step-Growth Polymerization of Methoxystyrenes by Rare-Earth Catalysts.
- Source :
-
Angewandte Chemie International Edition . 11/14/2016, Vol. 55 Issue 47, p14812-14817. 6p. - Publication Year :
- 2016
-
Abstract
- The simultaneous chain-growth and step-growth polymerization of a monomer is of great interest and importance because it can produce unique macromolecules which are difficult to prepare by other means. However, such a transformation is usually difficult to achieve in one polymerization system because chain-growth polymerization and step-growth polymerization proceed by different reaction mechanisms. Reported here is the simultaneous chain-growth and step-growth polymerization of para- and meta-methoxystyrenes catalyzed by half-sandwich rare-earth alkyl complexes, and the step-growth polymerization proceeds by the C−H polyaddition of anisyl units to vinyl groups. This unprecedented transformation affords a new family of macromolecules containing unique alternating anisole-ethylene sequences. In contrast to para- and meta-methoxystyrenes, ortho-methoxystyrene exclusively undergo syndiospecific, living chain-growth polymerization by continuous C=C bond insertion to give perfect syndiotactic poly(ortho-methoxystyrene) with high molecular weight and narrow polydispersity (rrrr >99 %, Mn up to 280 kg mol−1, Mw/Mn <1.10). [ABSTRACT FROM AUTHOR]
- Subjects :
- *POLYMERIZATION
*MONOMERS
*MACROMOLECULES
*ANISYL group
*ALKYL group
Subjects
Details
- Language :
- English
- ISSN :
- 14337851
- Volume :
- 55
- Issue :
- 47
- Database :
- Academic Search Index
- Journal :
- Angewandte Chemie International Edition
- Publication Type :
- Academic Journal
- Accession number :
- 119457459
- Full Text :
- https://doi.org/10.1002/anie.201609065