Doctoral Degrees (Chemistry and Polymer Science)

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Browsing Doctoral Degrees (Chemistry and Polymer Science) by Subject "Acrylates"

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    Synthesis, polymerisation and characterisation of a novel olefin-modified acrylate monomer, 1-methyl-1-propyl-hexel acrylate
    (Stellenbosch : Stellenbosch University, 2005-03) Mange, Siyabonga; Sanderson, R. D.; Tonge, M. P.; Stellenbosch University. Faculty of Science. Dept. of Chemistry & Polymer Science.
    ENGLISH ABSTRACT: Finding use for byproducts from the chemical industry holds many advantages for a country's economy. Synthesis of new monomers from such byproducts adds value to otherwise otherwise low-value material. The synthesis of a new olefin-modified acrylate monomer, 1-methyl-1-propyl-hexyl acrylate (1-MPHA), derived from 1-pentene, is reported. Homopolymerisation of the monomer 1-MPHA was carried out in both benzene and in toluene. The products of full-conversion of the homopolymer poly-(1-MPHA) were characterised by GPC, NMR, TGA and DMA. Kinetic studies of the homopolymerisation process of 1- MPHAwere also undertaken. The monomer 1-methyl-1-propyl-hexyl acrylate (1-MPHA) was copolymerised with methyl methacrylate (MMA). Samples obtained from full conversion copolymerisations at various 1-MPHAIMMAfeed ratios were characterised by GPC, NMR, TGA and DMA. Reactivity ratios of the two monomers were obtained from in situ 1H NMR kinetic studies. 1-MPHA was also copolymerised with vinyl acetate (VAc). Samples obtained from full conversion copolymerisation with a 1-MPHA content ranging from 2 to 16 wt% were characterised by GPC, NMR, TGA and DMA. The solubility parameter and the hydrophobicity of the VAc/1-MPHA copolymers were also determined. Reactivity ratios of the two monomers were obtained from in situ 1HNMR kinetic studies. Further copolymerisation studies with styrene and glycidyl methacrylate as comonomers were undertaken. The chemical analysis and thermogravimetric analysis of the copolymers are reported. In conclusion, the use of 1-methyl-1-propyl-hexyl acrylate as a comonomer results in a reduction in the glass transition temperature, better thermal stability, increased hydrophobicity with an insignificant loss in stiffness of the copolymers. These properties are due to the long and branched chain structure of the 1-MPHA monomer.