(Stellenbosch : Stellenbosch University, 1999-12) Geldenhuys, Monja; Sanderson, R. D.; Brall, R.; Stellenbosch University. Faculty of Science. Dept. of Chemistry & Polymer Science.
ENGLISH ABSTRACT: This study concerns the copolymerization of ethylene and propylene with I-pentene
using metallocene-based zirconium catalysts. A thorough study on the background of
the copolymerizations of I-pentene with ethylene and propylene was done.
The metallocene catalyst that was used in the copolymerization of ethylene with
I-pentene was the isospecific rac-[ethylene bis(l-indenyl)]zirconium dichloride
(rac-Et(Ind)2ZrCl2) catalyst, and in the copolymerization of propylene with I-pentene
the silylene-bridged catalyst, rac-Me2Si(2-MeBenz[e]Ind)2ZrCl2. Methylalumoxane
(MAO) was used as cocatalyst in all the polymerizations.
Characterization of these copolymers included determinations of the thermal
properties, microstructures, molecular masses and molecular mass distributions. In
particular the relationship of the amount of I-pentene incorporated in the copolymers
on the thermal properties was investigated. The short-chain branching of these
copolymers was investigated by crystallization analysis fractionation (CRYSTAF).