RELATIVE REACTIVITIES OF HYDROCARBON MONOMERS IN THE CATIONIC COPOLYMERIZATION INITIATED BY THE HCL-ALCL3-XYLENE COMPLEX

Citation
Ac. Magni et M. Corbellini, RELATIVE REACTIVITIES OF HYDROCARBON MONOMERS IN THE CATIONIC COPOLYMERIZATION INITIATED BY THE HCL-ALCL3-XYLENE COMPLEX, Gazzetta chimica italiana, 123(8), 1993, pp. 449-455
Citations number
44
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Chemistry
Journal title
ISSN journal
0016-5603
Volume
123
Issue
8
Year of publication
1993
Pages
449 - 455
Database
ISI
SICI code
0016-5603(1993)123:8<449:RROHMI>2.0.ZU;2-F
Abstract
The relative reactivities of 22 unsaturated hydrocarbons in the cation ic copolymerization initiated by the HCl-AlCl3-xylene complex have bee n investigated by generalizing the Wall equation to a multicomponent c opolymerization system. A reactivity scale has been derived that agree s with data reported in the literature for two-component copolymerizat ion systems. The reactivity of aliphatic olefins and isolated dienes c ould be satisfactorily explained in terms of steric and inductive effe cts of alkyl substituents on the double bond. 1,3-dienes and aromatic olefins showed a more complex behaviour; the stereochemistry of the co njugated double bond system seems to be the most important factor infl uencing reactivity, the s-cis conformation being more reactive than th e s-trans. A reaction mechanism involving initial formation of a pi-bo nded species between monomer and electrophilic centres transforming in to a new carbenium ion is supported by the experimental data.