The work presented in this thesis reports the development of a non-stick coating for bakeware from renewable materials. Also investigated is the use of epoxidised vegetable oils for renewable polyesters and nanocomposites. Chapter 1 provides a brief introduction to materials from renewable sources leading to a more detailed overview of triglyceride chemistry and finishes with a brief background of non-stick coatings. Chapter 2 presents the development of the non-stick coating. Current commercial coatings were analysed identifying the key components that could be replaced with more environmentally friendly alternatives. Thermal and photo-initiated curing regimes were studied on a range of epoxidised vegetable oil monomers for use as a polymer binder. Thermally cured epoxy soybean oil using a sulfonic acid catalyst was deemed superior. Additives to this resin such as silica, pigments and solvents were investigated to produce a coating formulation which was analysed by TGA and industry standard surface tests including pencil hardness, flexibility and cross-hatching. Chapter 3 reports the hydrosilylation reaction on vegetable oils. A model system with fatty acids and triethylsilane was proposed which lead to the formation of crosslinked silicone rubbers using di- and polyfunctional silanes and vegetable triglycerides. Epoxy fatty acid – silicone hybrids were used as release agents in the non-stick coating formulation described above. Chapter 4 focuses on the ring opening polymerisation of epoxidised vegetable oils with cyclic anhydrides forming crosslinked polyesters. Mechanical properties such as tensile strength, elasticity and Young’s modulus were measured as well as thermal analysis (TGA, DSC and DMTA). It was found that the physical properties were related to the crosslinking density with a higher density lead to strong but brittle polymers whereas lower crosslinking density samples were soft and elastic. The crosslinking density could be controlled by the choice of the vegetable oil type, anhydride type and the epoxide : anhydride ratio. Chapter 5 uses these polyester resins in the formation of nanocomposites. Nanocomposites were created using hollow silica shells and polyaromatic hydrocarbons and the mechanical properties measured and compared to the vegetable oils resins alone and other work in this area. This was followed by the copolymerisation of epoxy vegetable oils and styrene oxide and blends of grapessed and euphorbia oils with different epoxide functionality. It was found that blends could achieve properties of both oils such as high strength and elasticity in the same polymer sample. Chapter 6 describes the experimental procedures and chemical analysis of reactions performed in this thesis.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:687164 |
| Date | January 2015 |
| Creators | Ross, Andrew Henry |
| Publisher | University of Warwick |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://wrap.warwick.ac.uk/79959/ |
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