Preparation and evaluation of the mixtures of sulfonate and phenate as lube oil additives

Lubricating oil additives impart new properties to oil or reinforce desirable properties already possessed by the oil. They are used to prevent sludge and varnish deposits in engines, to inhibit rust and corrosion, and to minimize wear and friction. Detergents, especially basic detergents, contain reserve base that will neutralize the acids, while this decreases the corrosive tendency of the acids formed at high temperatures. Dispersants also disperse sludge formed in engine operated at low temperature. In the present work, neutral, basic, and overbasic calcium salt of sulfurized dodecyl phenol and neutral calcium sulfonate were prepared and evaluated as antioxidant and detergent/dispersants. Also, different metallic mixtures were prepared via mixing dodecyl benzene sulfonic acid and neutral calcium salt of dodecyl phenol in different ratios. Then basic and overbasic of corresponding mixtures were prepared using excess of calcium hydroxide and carbon dioxide. The efficiency of the prepared compounds as detergent/dispersant additives for lubricating oil wasinvestigated. It was found that the prepared additives have excellent power of dispersion and detergency and this efficiency increases by increasing basicity, percentage of calcium salt, and the ratio of dodecyl benzene sulfonic acid in the mixture.