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Synthesis,Characterization and Evaluation of Nano-Modified Polymeric Materials from Yellow Oleanda (Thevetia peruviana) Seed Oil

Siyanbola, T. O. (2014) Synthesis,Characterization and Evaluation of Nano-Modified Polymeric Materials from Yellow Oleanda (Thevetia peruviana) Seed Oil. ["eprint_fieldopt_thesis_type_phd" not defined] thesis, Covenant University.

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The use of sustainable and biodegradable resources in the preparation of diverse industrial materials (such as organic coatings) has been revitalized due to emerging environmental challenges faced by today’s world. Plant oils are considered the most available and renewable resource material, capable of replacing the petroleum feed-stock (petrochemicals), used in the preparation of most polymeric materials. The present report presents the synthesis, characterizations and evaluations of nano-modified polymeric materials from Thevetia peruviana seed oil (TPSO). The triglyceride based monomers were prepared through aminolysis and partial glyceride (PG) formation from TPSO. The fatty-amide of the oil (N,N-bis (2-hydroxy ethyl) Thevetia peruviana seed oil fatty-amide {HETA}) as well as desaturated fatty-amide methylesters of the oil (desaturated N,N-bis (2-hydroxy ethyl) Thevetia peruviana seed oil fattyamide {DHETA}) were treated with isophthalic acid and polyesteramides of their respective esterification were obtained. Partial glycerides polyol formation was carried out by reacting TPSO with glycerol in the presence of CaO as catalyst. These polyols were further reacted with 4,4'-diisocyanatodicyclohexylmethane (H12 MDI) to synthesize pristine polyurethanes. Nano particles (zinc oxide {ZnO} and 3-aminopropyltrimethoxylsilane-zinc oxide {APTMS-ZnO}) were also dispersed within the polymer matrix. The formation of monomers, pre-polymers as well as the eventual polymer composites were structurally elucidated by Fourier Transform Infrared Spectroscopy (FT-IR), Proton Nuclear Magnetic Resonance (1H NMR) and Carbon 13 Nuclear Magnetic Resonance (13C NMR) spectroscopic techniques. The fatty acid profile of TPSO fatty acid methyl esters (FAMEs) was examined by GC-FID. Thermal stability and curing of the hybrid composites were examined by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical thermal analyzer (DMTA). The surface morphology and crystal/amorphous nature of the hybrid films was studied with scanning electron microscopy (SEM) and X-ray diffractometry (XRD) respectively. Anticorrosive (in acid, alkali, water, xylene and salt spray fog test), solubility test and antimicrobial (Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Aspergillus niger and Klebsiella pneumonia) properties of the films were investigated. Results revealed that the fatty acid composition of the oil comprised mainly oleic (48.2 %), palmitic (22.3 %), linoleic (19.8 %) acids. FT-IR, 1H and 13C NMR confirmed the formation of the expected polymer matrices and their corresponding nanomodified composites, indicating a successful incorporation of the nano-material (APTMS-ZnO) in the pristine polymer coatings. The impregnation of the nano-material in the polymer led to curing of the polymer at room temperature. Results further revealed that as the percentage composition of the synthesized and incorporated nano-particle in the polymer matrix increased, properties such as thermal stability, anticorrosive and antimicrobial properties of the polymeric coatings also increased. However, at higher percentages, agglomeration of the nano-particle within the polymeric matrix ensued (for example in the case of PUTFA (Polyurethane Thevetia fatty amide)-APTMS-ZnO {15 wt %}). This made the micrograph of the film to be rough and also affect the thermal stability of the coatings. The successful incorporation of modified nanoparticle within the pristine polymer had positive influence of the thermal stability, chemical resistance and antimicrobial inhibition on organisms tested. The coatings retain their photographic transparency irrespective of the varying inorganic–organic nano-particle within the polymer matrix.

Item Type: Thesis (["eprint_fieldopt_thesis_type_phd" not defined])
Subjects: Q Science > QD Chemistry
Divisions: Faculty of Engineering, Science and Mathematics > School of Chemistry
Depositing User: Mr Solomon Bayoko
Date Deposited: 21 Jan 2015 18:52
Last Modified: 21 Jan 2015 18:52

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