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dc.contributor.authorMarx, Frans T.I.
dc.contributor.authorVosloo, Hermanus C.M.
dc.contributor.authorPieters, Esna
dc.date.accessioned2019-07-12T09:50:29Z
dc.date.available2019-07-12T09:50:29Z
dc.date.issued2018
dc.identifier.citationMarx, F.T.I. et al. 2018. Oligomerisasie van langerketting 1-alkene in die teenwoordigheid van Cp2MCl2-metalloseen-, meer komplekse Zr-metalloseen- en tridentaat bis(imino)piridienyster(II)-katalisatorsisteme. LitNet akademies, 15 (3). [https://www.litnet.co.za/wp-content/uploads/2018/10/LitNet_Akademies_15-3_Marx-Pieters-Vosloo.pdf]en_US
dc.identifier.issn1995-5928 (Online)
dc.identifier.urihttp://hdl.handle.net/10394/32875
dc.identifier.urihttps://www.litnet.co.za/wp-content/uploads/2018/10/LitNet_Akademies_15-3_Marx-Pieters-Vosloo.pdf
dc.description.abstract1-alkenes represent a large part of the commercial market and since oligomers thereof are important intermediates for specialty chemicals, they warrant further study. Metallocene catalysts are a promising development, since metallocenes, such as Cp2ZrCl2 (Cp = cyclopentadienyl), are easily obtainable. Examples of the oligomerisation of higher 1-alkenes are limited and there is a shortage of in-depth studies on these types of catalysts [3, 8–39]. It is also very apparent that only low MAO loadings lead to the formation of oligomers, and at higher loadings, polymerisation takes place [3, 18–29]. In an effort to increase the knowledge base of the oligomerisation of 1-alkenes a series of Cp2MCl2-catalysts (M = Zr (1), Ti (2), Hf (3) and Nb(4)), more complex Zr-metallocene (5 to 7) and tridentate bis(imino)pyridine iron(II) (8 to 11) catalyst systems was investigated (Figure 4). The specific aim was to determine the oligomerisation activity and selectivity of these catalysts in the presence of MAO as co-catalyst. Several factors can influence the catalyst activity during the conversion of 1-alkenes, namely activation temperature (Ta), activation time (ta), reaction temperature (Tr), co-catalyst concentration, the transition metal (M), and the monomer (mo) concentration. All these factors were investigated for the metallocene catalysts (1 to 4). The choice of ligand and bridging compound of the metallocene catalysts influenced the properties of the polymers obtained during reactions. The three more complex metallocene catalysts, 5 to 7, were investigated for their ability to oligomerise higher 1-alkenes. An important development in 1-alkene polymerisation catalysts was the discovery of the Group 8 iron catalysts, the so-called neutral tridentate bis(imino)pyridine iron(II) catalysts. Four catalysts of this type, 8 to 11, were identified for investigation of their activity with regard to the oligomerisation of higher chain 1-alkenes. Many factors can influence the catalyst activity during the conversion of 1-alkenes; in this study, only the reaction temperature (Tr) and co-catalyst concentration were varied because they were found to be major factors in determining the catalytic activity. The activity of the catalysts and degree of oligomerisation (n) were investigated with regard to 1-heptene and 1-octeneen_US
dc.description.abstractDie oligomerisasievermoë van ’n reeks Cp2MCl2-metalloseen- (Cp = siklopentadiëniel, η 5 -C5H5; M = Zr, Ti, Hf en Nb), meer komplekse Zr-metalloseen- en tridentaat bis(imino)piridienyster(II)- katalisatorsisteme is ondersoek. Verskeie faktore wat die katalisatoraktiwiteit van die Cp2MCl2- metalloseen-katalisatorsisteme gedurende die omskakeling van 1-alkene kan beïnvloed, is nagegaan. Die faktore is: aktiveringstemperatuur (Ta), aktiveringstyd (ta), reaksietemperatuur (Tr), kokatalisatorkonsentrasie, die tipe oorgangsmetaal (M) en die monomeerkonsentrasie (mo). Die temperatuur, die oorgangsmetaal en die kokatalisatorkonsentrasie het die reaksietempo en die graad van oligomerisasie dramaties beïnvloed. Die twee faktore wat die reaksietempo en graad van oligomerisasie dramaties beïnvloed het, naamlik die kokatalisatorkonsentrasie en die reaksietemperatuur (Tr), is verder met die meer komplekse Zr-metalloseen- en tridentaat bis(imino)piridienyster(II)-katalisatorsisteme ondersoek. Uit die drie reekse katalisatore wat ondersoek is, is vier geïdentifiseer wat die hoogste aktiwiteit getoon het, en die potensiaal het om vir die dimerisasie van langerketting 1-alkene gebruik te kan word
dc.language.isoenen_US
dc.publisherLitNeten_US
dc.subject1-Alkeneen_US
dc.subjectGebrugde metalloseneen_US
dc.subjectMetalloseendichloriedkatalisatoren_US
dc.subjectMetielaluminoksaanen_US
dc.subjectOligomerisasieen_US
dc.subjectyster(II)-katalisatoren_US
dc.subjectBridged metallocenesen_US
dc.subjectMetallocene dichloride catalysten_US
dc.subjectMethylaluminoxaneen_US
dc.subjectOligomerizationen_US
dc.subjectIron(II)-complexen_US
dc.titleOligomerisasie van langerketting 1-alkene in die teenwoordigheid van Cp2MCl2-metalloseen-, meer komplekse Zr-metalloseen- en tridentaat bis(imino)piridienyster(II)-katalisatorsistemeen_US
dc.typeArticleen_US
dc.contributor.researchID10063552 - Vosloo, Hermanus Cornelius Moolman
dc.contributor.researchID12582697 - Marx, Frans Thomas Ignatius


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