The Degradation and Stabilisation of Epoxide Resins to Ultraviolet Radiation


This thesis was an investigation of the chemical and physical changes which occurred on exposure of two epoxide resins, one amine and the other anhydride cured, to ultraviolet light. The method of study was by investigation of the changes in both cured resins and the monomers from which they were synthesised. Also, because of the intractable nature of the cured structures, the degradation of a number of model compounds which were structurally similar to the cured systems were investigated. The results showed that the monomer itself was susceptible to the radiation used. Monomer purity decreased the rate but it did not eliminate the degradation process. From quantum yields studied, the initiation was found to result in a non-chain reaction. The extent of degradation was proportional to the intensity of the light used. No "dark" chemical reactions were observed to occur with any of the compounds studied, although "dark" physical reactions by diffusion of degradation products did occur in the cured structures. The wavelengths of light causing maximum degradation were contained in the short wavelength region of the lamp. In the anhydride cured resins the 365 nm band was also found to contribute to the overall degradation process. The photo-oxidative degradation resulted in the formation of an oxidised surface layer of material from crosslinking reactions involving atmospheric oxygen. Volatile compounds were evolved during irradiation and their rate of concentration change confirmed the surface layer theory, as did measurement of the torsion modulus of the cured systems. Complete stabilisation of the materials with existing stabilisers, and new synergistic mixtures failed. However it was possible to decrease the rate of degradation in both the amine and anhydride cured polymers.

Divisions: College of Engineering & Physical Sciences > School of Infrastructure and Sustainable Engineering > Chemical Engineering & Applied Chemistry
Additional Information: Copyright © Doyle, 1972. M.J. Doyle asserts their moral right to be identified as the author of this thesis. This copy of the thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without appropriate permission or acknowledgement. If you have discovered material in Aston Publications Explorer which is unlawful e.g. breaches copyright, (either yours or that of a third party) or any other law, including but not limited to those relating to patent, trademark, confidentiality, data protection, obscenity, defamation, libel, then please read our Takedown Policy and contact the service immediately.
Institution: Aston University
Uncontrolled Keywords: degradation,stabilisation,epoxide resins,ultraviolet radiation
Last Modified: 08 Dec 2023 08:01
Date Deposited: 11 Jan 2011 13:52
Completed Date: 1972
Authors: Doyle, Michael J.

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