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Homo‐ and copolymerization of ethylene with highly active catalysts based on TiCl 4 and grignard compounds
Author(s) -
MuñozEscalona A.,
García H.,
Albornoz A.
Publication year - 1987
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.1987.070340309
Subject(s) - comonomer , copolymer , catalysis , polymerization , polymer , materials science , ethylene , monomer , polymer chemistry , active center , chemical engineering , chemistry , organic chemistry , composite material , engineering
In this paper, the synthesis of different catalytic systems based on the reduction of TiCl 4 by Grignard compounds has been systematically studied. The catalysts exhibited the highest activities when used in the copolymerization of ethylene with n ‐hexene. The profile of the kinetic curves also changed when the comonomer was present during polymerization. By thermal analysis and scanning electron microscopy techniques, it could be found that the incorporation of the comonomer to the polymer chain brings about a decrease in the polymer crystallinities and an increase in the porosities of the growing particles. Due to that, the diffusion of the monomer to the catalytic active centers takes place more easily, consequently increasing the polymerization rate. In addition, catalysts control better the morphology (size and shape) of the nascent polymer particles when used for copolymerization.