Wax crystal formation in diesel and related hydrocarbon fuels during cold weather is a long standing problem. Current polymeric additives to diesel fuel modify the crystal habit of the wax, in a variety of ways, to improve its performance at low temperature. These wax crystal modifiers (WCM) have to operate at low concentrations (0.01-0.1%) to make their use economical, so it is critical that their structures are optimised for the application. The objectives of this work was to synthesise, characterise and test some new polymeric additives which are anticipated to effect the crystallisation of the wax from the fuel and to prepare a model ethylene vinyl acetate (EVA) polymer to gain insights into the mode of action of the EVA co-polymers which are currently in use as WCM. Ring opening metathesis polymerisation was chosen as the method of preparation for these new polymeric additives. An introduction to wax crystallisation in diesel fuel and some proposals for the preparation of these new polymeric additives are given in Chapter 1. Chapter 2 discusses olefin metathesis and ring opening metathesis polymerisation reactions. The synthesis and characterisation of monomers and polymers are given in Chapters 3 and 4 respectively. Results from fuel tests are described in Chapter 5
