改性大豆油配方的氧化安定性研究

选用碱炼大豆油和三种基因改性大豆油作为基础油，采用加压差示扫描量热（PDSC）和旋转氧弹（RBOT）试验考察了四种改性大豆油中的起始氧化温度、不同添加剂配方对改性大豆基础油氧化安定性的影响以及基础油和降凝剂对改性大豆油低温流动性能的影响。结果表明，改性大豆油的不饱和脂肪酸含量越高，其氧化安定性越差；抗氧剂二戊基二硫代氨基甲酸锌和抗磨剂二烷基二硫代氨基甲酸锑在改性大豆油中均表现出了良好的抗氧协同性能，尤其在基因改性大豆油中，聚-α-烯烃和添加剂的复配使其起始氧化温度和氧化诱导时间均超过了相同配方的聚-α-烯烃油样。倾点试验结果表明，聚-α-烯烃和降凝剂的加入还可以明显提高改性大豆油的低温流动性能。

STUDY ON THE OXIDATION STABILITY OF MODIFIED SOYBEAN OIL FORMULATIONS

The thermal oxidation stabilities of 4 modified soybean oils (including three genetically modified soybean oils) and their formulated oils were evaluated by pressurized differential scanning colorimeter (PDSC) and rotary bomb oxidation test (RBOT). Test results showed that the oxidation stability of modified soybean oils decreased with the increase of unsaturated fatty acid content. Zinc diamyl dithiocarbamate (ZDDC) antioxidant showed good synergism with antimony diakyl dithiocarbamate (SbDDC) antiwear additive in improving the oxidation stability of modified soybean oils. The incipient oxidation temperature (IOT) and induction period time (IPT) of genetically modified soybean oils were improved significantly by adding polyalphaolefin (PAO) and additives, and they were even better than that of the synthetic base oil PAO with the same additive formulation. Furthermore, the pour point test results showed that the addition of PAO and pour point depressant could effectively improve the low temperature fluidity of modified soybean oils.