Syntheses and investigations of copolymers for improving the flow of middle distillate oils

The results of a review of the patent literature on polymeric flow improvers for distillate fuels showed that a diverse range of polymeric compositions is effective. Ethylene-containing compositions predominate and of these ethylene-vinyl acetate (EVA) copolymers are the most common. Ethylene-vinyl acetate copolymers were synthesised using a high pressure autoclave. The effectiveness of the copolymers varied greatly with the chemical composition of the copolymer. The techniques described in the literature for the determination of the composition of EVA copolymers are summarised and reviewed. A new technique using proton nuclear magnetic resonance was developed. A statistical analysis of the results is presented.