Abstract
A number of novel oligomeric alkenyl functionalised cyanate ester monomers were synthesised and characterised. These were designed to be incorporated into blends of commercial bismaleimide and cyanate ester resins as modifiers, with the aim of improving the glass transition temperature of these systems, whilst retaining or improving on their comparatively high fracture toughness. The thermal analysis of the monomers and blends is described, demonstrating the reaction of the functionalised cyanates with bismaleimides, and the potential increase in glass transition temperature resulting from the incorporation of these modifiers into cyanate/bismaleimide blends. Carbon fibre reinforced composite samples were prepared, and the results of a number of mechanical tests including mode 1 fracture toughness are given. The advantages and disadvantages of a number of resin blends based on the novel modifiers synthesised during this work, are discussed. Chapter 1 gives a brief introduction to engineering polymers and carbon fibre composites, then outlines the aims of this work more specifically. Chapter 2 first discusses the approach taken to the synthesis of the novel modifiers and then gives precise details of the syntheses. Chapter 3 introduces the thermal analysis methods used and gives the results of those analyses. Chapter 4 describes the methods used for the preparation of carbon-fibre reinforced composite samples (based on the new modifiers), the mechanical test procedures and the results of those tests. Chapter 5 concludes by bringing together the results of the thermal analysis and composite studies, and suggests topics for further research.