Abstract
Adhesives have commonplace use in the industrial and domestic environments, but loss of adhesion occurring from long-term use is still one problem that has not been solved by the adhesives industry. One mode of failure of adhesion is thought to be the presence of 'kissing bonds', also known as 'zero-volume unbonds', ZVUs. At present kissing bonds are not much more than a theoretical concept applied to the mechanism of adhesive failure, with little experimental evidence to support their existence or the mechanism of formation. The aim of this PhD thesis is to evaluate novel methods of developing a self-validating, responsive side group polymer, which can automatically repair interfacial failure. This can be used in the future as a tool to help evaluate the concept and mechanisms of kissing bonds. Primarily, it is hoped that the model systems will be used as a solution to the problem of kissing bonds in the form of a self repairing adhesive. The focus of this research has concentrated on the synthesis and characterisation of a novel responsive polymer, which incorporates a secondary component that can be released upon the ingress of water, and will diffuse to the area of failure. Once there, the secondary component should be able to repair or eliminate the kissing bond, through chemical reaction. The ingress of water is to be used as the catalyst for the release of the secondary component, as this process of ingression over a period of time has been hypothesised by Allsop et al1 to contribute to the occurrence of kissing bonds at the adhesive-adherend interface. This thesis will discuss the synthesis, characterisation and evaluation of novel ionic methacrylate copolymers, poly[methyl methacrylate-co-N,N-2-(dimethylamino)ethyl methacrylate], incorporating an ionically bonded polymerisable secondary component based upon three acidic monomers, methacrylic acid, MA, vinylphosphonic acid, VPA and 2-methaciyloyloxyethyl phosphate, MOEP. It will document the incorporation of the quaternary salt into a secondary matrix based upon a diglycidyl ether of bisphenol-A followed by characterisation and testing of the model adhesive system.