Abstract: A series of polyether amine(PEA) detergents with different polymerization monomers, different degrees of polymerization and different amino-terminated structures were synthesized by the method of amine protection, the structures of polyether amines were characterized by HRMS, NMR and IR, and their detergency were compared, furthermore, the structure-activity relationship of PEAs was studied by establishing detergent model, gasoline model and coke model with Material Studio software. The results showed that the detergency of polyetheramine was closely related to the structure of polar group in its head and the structure of polymerization unit. When the molecular structure was the same, polyether amine with average number molecular weight about 1 000 had the best detergency; when polar groups were the same, the PEAs with higher proportion of epoxy butane had better detergency, and PEAs with pure epoxy butane chain had the best detergency; when the polymerization unit structures were the same, the order of detergency of the different amino-terminated detergents from high to low was mono-primary amine polyether amine > di-primary amine polyether amine ≈ N,N-dimethyl-1,3-propanediamine-terminated polyether amine. The results of molecular simulation showed that the adsorption energy between the head polar group and the carbon deposit, the interaction energy between the polyepoxide alkane chain and the fuel oil determined the detergency of polyether amine.

Key words: engine, fuel oil, deposit, detergent, polyether amine, structure-activity relationship