Doctoral Degrees (Chemistry)

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Browsing Doctoral Degrees (Chemistry) by Subject "Amide and amine functionalised benzo-15-crown-5"

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    A new method to remove and recover contaminating sodium salts from industrial wastewater utilising polymer-bound crown ethers
    (University of the Free State, 2001-11) Koortzen, Johannes Gerhardus; Swarts, J. C.
    English: The aim of this study was to develop a new technique to clean the total factory generated wastewater as seen in the light of the background given in Chapter 1. It was decided to develop a material that would enable an industry to complex sodium cautions from a contaminated source, and to release the complexed sodium cautions, under controlled conditions, at a previously determined site, or receiving reservoir, in a cyclic manner. For this reason, 32 different functionalised crown ether derivatives were synthesised to produce a series of 17 new crown ether derivatives, including 4 carboxylic acid, 4 amide, 4 alcohol and 4 amine crown ether derivatives, with spacer ranging from one to four carbon atoms in the side chain that separate the functional group from the crown ether moiety. Selected crown ether functionalised derivatives was anchored on polymeric supports and their sodium caution complexation ability was determined. Twenty (20) polymeric carriers were also synthesised. These include the synthesis of 12 new water-soluble polyaspartamide derivatives as well as 5 new polyepichlorohydrin water-insoluble derivatives. The experimental procedures for the synthesis of the water-soluble polymers could be tuned to achieve exact ratios between polymer anchored crown ethers and several other polymer side chains containing functional groups. The carboxylic acid derivatives could be anchored to the water-soluble polymer and this reaction could be tuned to achieve 100 % coupling, with the use of the coupling reagent O-benzotriazolyl-N,N,N',N'- tetramethyluronium hexafluorophosphate. An elastomeric solid support was also synthesised by the curing of hydroxy terminated polybutadiene with isophorone diisocyanate. It was also demonstrated that crown ether derivatives and/or polymeric carriers could be anchored onto this elastomeric solid support, with or without the use of a spacer between the elastomeric solid support and the crown ether. Several new elastomeric solid supports containing crown ethers were synthesised. Complexation studies of Na+ dissolved in an aqueous phase by crown ether functionalised elastomeric solid supports were demonstrated, and it was found that 1.28 g Na+ I m2 surface area of the sodium caution scavenging device could be removed. Acid media was used to accomplish the release of the Na+ from this elastomeric solid support, and it was found that 0.65 g Na+ I m2 surface area of the sodium caution scavenging device could be released.