Use this URL to cite or link to this record in EThOS: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.800805
Title: Suitability of a linseed oil epoxy resin for composite applications
Author: Benega, Marcos Antonio Gimenes
Awarding Body: University of Southampton
Current Institution: University of Southampton
Date of Award: 2019
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Abstract:
Vegetable oils are a great sustainable source for the production of resins. When these oils are epoxidized, their viscosities are greatly increased which prevents their use in the production of composites, especially via resin transfer moulding and infusion. This work studies aspects of the synthesis, curing and properties of cured epoxy resins derived from linseed oil. Two versions of the resin are used; the first comprising the epoxidized triglycerides of linseed oil (ELO), the second a low-viscosity version (TELO) obtained from the transesterification of ELO in methanol. The synthesis is initially carried out with heterogeneous catalysts such as TS-1 and Ti-SiO2. These catalysts show great activity towards epoxidation of fatty acid methyl esters (FAMEs), yet the epoxidation and transesterification of triglycerides was limited; a homogeneous synthesis is then used in larger batches. Two curing approaches are used for ELO and TELO. The first consisted of blending them with conventional epoxy resin (DGEBA) cured by conventional and phenalkamide hardeners. The phenalkamide was chosen after a comparison of five different commercial phenalkamide and phenalkamine hardeners. The second curing procedure was done using a blend of ELO and TELO with a commercial UV-curable resin derived from linseed oil. FT-IR and gel fraction tests show that all samples reached a high degree of curing. The use of TELO greatly reduces the viscosity of the blends but there are also reductions in elastic modulus, tensile strength and glass transition temperature. The long fatty acid chains in ELO and TELO have a plasticizing effect. The glycerol fragment connecting the fatty acid in ELO is essential for a high crosslinking density. The use of linseed oil derived epoxy resins in composite structures is limited. The conventional epoxy systems still have better properties yet to be achieved by bio-based ones.
Supervisor: Blake, James Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.800805  DOI: Not available
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