Composition And Effect Study Of Alkyl Salicylates Additive Packages In New Kind Medium Speed Engine Oil

The additive package is the key factor of medium speed engine oil properties which will decide whether the engine oil can perform well in a long time. However, the difference of manufacturers, raw materials would lead to big diversity of engine oil in many aspects, water separation, for example. Therefore, it is necessary to study how these additives will effluence the properties of medium speed engine oil. This research is very important to additive manufacture and compounding work.Rubber membrane dialysis, column chromatography and other separated ways are used to separate these five medium speed engine oil additive packages, which are A, B, C, D and E. Element analysis, IR, NMR, MS and some other analyze ways are used to research the composition and structure characteristics of these additive packages. Meanwhile, the properties (detergency, extreme pressure and anti-wear, water separate, etc) are also detected to find how the additives effluence their usability.The research results show that these five additive packages are all salicylate additive packages. All these five additive packages are consisted by two kinds of calcium alkyl salicylate which have different polarities. Besides, there is still a kind of ZDDP additive in package E. The structure information reveals that the calcium alkyl salicylates in these five packages are with obvious difference in average molecular weight and alkyl branched degree. And the less the alkyl branched degree is, the bigger the polarity of these additives is. The using performance of medium speed engine oil is decided by both the composition and the structure of the additives. There is no obvious difference in the detergency, storage stability of these packages. The water separation property is mainly influenced by the alkyl branched degree. The anti-water property is corresponded to colloidal stability and has no relationship with water separation property. The compatibility of these additives with sulfonate is showed antagonistic effect. The addition of ZDDP type additive would bring some negative effects to the water separation property.