Abstract
A number of functionalised cyanate esters are synthesised and characterised. These functionalised cyanate esters are investigated in resin blends with commercial bis-maleimide and cyanate ester resins in an attempt to improve the Mode I fracture toughness of commercial formulations whilst retaining the high glass transition temperatures of bis-maleimide formulations. Room temperature unidirectional carbon fibre composite data are presented and explanations for the observed physico-mechanical properties in terms of structure-property relationships are given.