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Predictions from the trigger mechanism for Ziegler‐Natta polymerization of α‐olefins
Author(s) -
Ystenes Martin
Publication year - 1993
Publication title -
makromolekulare chemie. macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 0258-0322
DOI - 10.1002/masy.19930660108
Subject(s) - monomer , polymerization , natta , polymer chemistry , chemistry , kinetics , copolymer , photochemistry , catalysis , polymer , organic chemistry , physics , quantum mechanics
The trigger mechanism is a new concept for understanding the polymerization of α‐olefins with Ziegler‐Natta catalysts. The mechanism is based on the interaction of two monomers in the transition state, where an incoming monomer triggers the insertion of a complexated monomer. The monomer site is never a free site, and is thus protected from attack by Lewis bases in the reaction medium. The stereochemical discrimination is due to the interaction of the two monomers. This interaction determines the orientation of the incoming monomer, and the stereochemistry of the insertion is given when the monomer is complexated. The model predicts a reaction rate order vs . monomer concentration between 1.0 and 2.0, a reduced overall polymerization rate above a given temperature, very complex kinetics for copolymerization, a lower stereochemical discrimination for the first inserted monomer, and a high stereochemical discrimination.