The use of IR spectroscopy to study the reaction of motor-oil additives

Conclusions

• 1. When succinimide is present together with zinc dialkyl- or diaryl-dithiophosphate or bisphenol No. 1 [2,2′-methylene-bis(4-methyl-6-tert-butylphenol)] as an additive, the components of such a mixture react; this is indicated by a change in the absorption frequencies and the molar extinction coefficients of the bands of the individual bonds when the additives are subjected to IR spectroscopy. ParaSuccinimide and bisphenol No. 2 (4, 4′-methylene-bis(2,6-di-tertbutylphenol)] are mutually inert; no change in the IR spectra of the additives is observed when they are present together.

• 2. A synergistic effect during solubilization of compositions of succinimide with antioxidizing additives of the bisphenol and zinc dithiophosphate type is observed only when the components of the mixture react. ParaThere are grounds for assuming that such a reaction is due to formation of a hydrogen bond, and that it leads to a specific change in the structure of the succinimide micelles.