Study On The Composition And Emulsification Performance Of Environmentally Friendly Marine Stern Tube Oil

The stern shaft sealing device often breaks down in shipping due to big shocks and sea damages,and it will cause oil leakage and environmental pollution.It is difficult for the traditional stern shaft oil to meet the requirements of environmental protection when it's stricter criterion.Therefore,it's urgent to develop environmentally friendly marine stern tube oil(EFMSTO)for shipping.Polyol ester as the base oil has the characteristics of good lubricity,excellent thermal stability,biodegradability and nontoxicity.In is paper the relationship between the structure of polyol ester and the performance of ship stern shaft oil is studied,and the base oil formulation was determined.Fuzzy analytical hierarchy process(FAHP)is utilized to study the complexing agent formulation.Effects on the emulsion stability like emulsifier types,dosage of emulsifier,shear rate,shearing time,types of co-emulsifier and dosage of co-emulsifier are researched with storage stability,centrifugal stability,the average droplet size and droplet size distributions as the evaluation index of emulsion stability,which resulted in optimal emulsifier formulation.Also,the performance of the oil and its emulsion such as extreme pressure antiwear property,hydrolytic stability and biological toxicity are tested.The results show that the base oil is blended by 2 kind of polyol ester,which can meet the requirements of the product base oil and economical.The complexing agent formulation meeting the quality requirements of the stern shaft oil is determined with optimal case in FAHP.The emulsion stability study showed that the increase of EO number and oil based carbon chain of hydrophilic emulsifier can enhance the stability of emulsion,and the synergistic effect reaches the best when the lipophilic group in hydrophilic emulsifier is similar to the hydrophilic group in lipophilic emulsifier.Meanwhile using polymer emulsifier can improve the stability of emulsion.Moreover increasing the content of emulsifier and co-emulsifiers,shear rate or shearing time can decreasing the average droplet size and increasing the storage time of emulsion.The environmental marine stern tube oil developed in this research shows a good consistency with the technical requirements of stern shaft oil.On the whole,the properties of the finished oil like extreme pressure antiwear properties,emulsion stability and hydrolysis stability are superior to those of the environmental-friendly stern shaft oil sold in market...