油酸甲酯对柴油机油热氧化性能影响研究

Effect of Methyl Oleate on Diesel Engine Oil about Thermal Oxidation

为研究生物柴油对柴油机油的影响,在柴油机油中分别加入质量分数10%和20%油酸甲酯,研究氧化前后油酸甲酯对柴油机油黏度、酸值和正戊烷不溶物含量的影响,量化了不同油酸甲酯含量对柴油机油各理化性能的影响百分比,从而得到不同油酸甲酯含量对柴油机油热氧化性能影响的总体百分比。结果表明:油酸甲酯的加入加快了柴油机油样品中高分子聚合物、酸性物质和正戊烷不溶物的生成,导致黏度和酸值增加;油酸甲酯对柴油机油酸值的影响最大,对黏度的影响其次,对不溶物含量的影响最小,说明加入油酸甲酯后,易较快地生成酸性物质是其诱导柴油机油氧化变质的主要原因;加入油酸甲酯越多,油酸甲酯对柴油机油热氧化性能的影响越大,这是因为随着油酸甲酯的逐渐加入,它的稀释作用会使柴油机油的性能衰减加剧。

In order to study the effect of biodiesel on diesel engine oil,methyl oleate of 10% and 20% at weight were added into diesel engine oil respectively.The effects of methyl oleate on the viscosity,acidity and n-pentane insoluble matter content of diesel engine oil before and after oxidation were studied.The percentage of different methyl oleate content on the physical and chemical properties of diesel engine oil was quantified,and the overall percentage of effect of different methyl oleate content on thermal oxidation properties of diesel engine oil was obtained.The results show that the formation of macromolecule polymers,acidic substances and n-pentane insoluble substances in diesel engine oil samples is accelerated after the addition of methyl oleate,which causes the increase of viscosity and acidity.Methyl oleate has the greatest impact on the acidity of diesel engine oil,the second is on the viscosity,and the least is on the insoluble substance content.This indicates that the formation of acidic substances is easy and fast after the addition of methyl oleate,which is the main reason for the oxidation deterioration of diesel oil.The more methyl oleate is added,the greater the influence of methyl oleate on the thermal oxidation performance of diesel oil is.This is because with the gradual addition of methyl oleate,its dilution will aggravate the performance degradation of diesel oil.