Study On Performance And Preparation Of Complex Barium Grease

Complex barium grease is a kind of multi-effect grease with high dropping point,good water washout characteristic and excellent extreme-pressure anti-wear property.The effects of different complex agents on the properties of complex barium grease are not fully studied.In this paper,the effects of different complex agents on barium grease were compared.The main contents of this study are as follows:Different barium greases are prepared by different proportions of two kinds of fatty acids(12-hydroxy stearic acid or stearic acid).The barium greases obtained are mixed with complexing agents to prepare different complex barium greases,whose dropping points are then measured.The structures of the greases are characterized by differential scanning calorimeter(DSC),X-ray diffraction(XRD),scanning electron microscopy(SEM)and fourier transform infrared spectroscopy(FTIR),and the relationship between the molecules of thickener and dropping point of greases is also studied.The friction,heat resisting and rheological properties of the greases are characterized by four ball machine,TGA and HAAKE rheometer,the effects of different complex agents on the structure and properties of complex barium greases are studied,which provides some theoretical basis for the preparation and research of the complex barium grease.The preparation process of complex barium grease with high dropping point was optimized.It is found that in the preparation of complex barium grease,the success rate of grease preparation could be greatly increased by replacing the aqueous solution of barium hydroxide octahydrate with the crystal powder of barium hydroxide octahydrate.The dropping points of barium greases complexed by sebacic acid,citric acid and adipic acid are relatively high.The high dropping point of the barium grease complexed by 12-hydroxy stearic acid with sebacic acid is due to the hydrogen bond formed between sebacic acid and barium 12-hydroxy stearate,which results in the formation of eutectic structure in the soap fiber.The hardness and viscosity of barium greases will increase after the addition of sebacic acid.The extteme-pressure anti-wear property of complex barium 12-hydroxy stearate grease is better than that of complex stearate grease.According to the study of friction properties of barium-based complex greases with polyacid,the anti-wear property of sebacic acid complex barium-based grease is the best.