Mannich bases and Phosphosulphurized Mannich bases: Synthesis, characterization and performance evaluation as potential lube oil additives

With increasing demands being placed on lubricants for automotive engines and transmissions, it has become necessary to improve the function of lubricants. Modem lubricants are formulated from a range of base fluids and chemical additives to improve their function or to add some new performance properties in them. In this study, some Mannich bases were prepared by using p-cresol, formaldehyde and different polyethylene polyamines. Phosphosulphurized Mannich bases were also prepared by the using P2S5. Structure of the prepared compounds has been confirmed by infrared spectroscopy, NMR and molecular weight determination. The performance of the prepared Mannich bases as well as their Phosphosulphurized derivatives was investigated as antioxidants and detergents/dispersants. It was found that the efficiency of additive performance increases with increasing the number of -NH groups in the amines used.