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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The synthesis of 1-butene oligomers with vinyl endgroups and their use in further reactions

Al-Aeeb, Ahmed 03 1900 (has links)
Thesis (MSc (Chemistry and Polymer Science))--University of Stellenbosch, 2007. / This study comprises the synthesis, functionalization, and characterization of 1-butene oligomers, as well as the synthesis of oligobutene-based macro-RAFT agent. The directed oligomerization of 1-butene was carried out with a Cp2ZrCl2 as a catalyst, activated with MAO as a co-catalyst (10% in toluene), in the ratio Al/Zr =1000/1. Oligomers possessing vinylidene double bonds, with low molecular weight (Mw), ranging between 800 and 2000 g.mol-1 as confirmed by gel permeation chromatography, were obtained. The oligomers were successfully functionalized by adding hydroxyl functionality to the vinylidene double bond using oxymercuration-demercuration reaction, and as a result hydroxy-terminated oligobutenes were obtained. Characterization techniques such as 1H NMR, 13C NMR, GC-MS and FTIR confirmed the successful synthesis and functionalization of 1-butene oligomers. The hydroxy-terminated oligobutenes were used to prepare an oligobutene-based macro-RAFT agent. The synthesis of the macro-RAFT agent was carried out with an esterification reaction between the hydroxy-terminated oligobutenes and an acid functionalized RAFT agent. The successful synthesis of the macro-RAFT agent was confirmed by 1H NMR, 13C NMR, FTIR, and UV spectroscopy. The chain transfer ability of the macro-RAFT agent to induce living characteristics in free radical styrene polymerization was investigated with respect to molecular weight control and kinetic behaviour. The macro-RAFT agent was identified as suitable RAFT agent, yielding polystyrene-b-oligobutnes with low polydispersities and molecular weight ranging from 3000 to 40000 g/mol.

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