化学改性豆油的烷链结构和摩擦学性能研究

The Alkyl Chain Structure and Tribology Characteristics of Chemically Modified Soybean Oil

本文对豆油进行了化学改性,豆油环氧后和不同链长的脂肪酸进行酯化反应,生成一系列的改性豆油并对其结构进行表征;考察了不同烷链结构的改性豆油的摩擦学性能,结果表明所合成的系列改性豆油有优良的摩擦学性能,随着直链酸链长的不同黏度也不同,黏度越大润滑性能越好,其中乙酯和丙酯的黏度最大、润滑性能最好,摩擦学性能远远优于豆油和光亮油150BS,归因于豆油异构乙酯和丙酯含有极性基团,且分子中氧的含量较高,易生成吸附膜和氧化反应保护膜.豆油异构丙酯倾点最低,其黏度高,可以代替紧缺的光亮油和低黏度油调配成多种不同黏度级别的润滑油.豆油异构丙酯与聚醚调配的各黏度级别的润滑油的倾点明显低于同级别矿物油,摩擦学性能优于同级别矿物油,氧化稳定性也远远优于矿物油,可用作高档次的合成润滑油.试验结果表明用本工艺改善植物油的氧化稳定性和润滑性行之有效.

A series of chemically modified soybean oil was prepared by epoxidizing soybean oil and fatty acids with different chain lengths through esterification reaction, and the molecular structure of chemically modified soybean oil was identified. Their tribological characteristics were evaluated and analyzed. And the acetyl - chemically - modified soybean oil was analyzed by Auger Electron spectroscopy （AES）. Results showed that the chemically modified soybean oils had good tribological characteristics. The chemically modified soybean oils with different acyl chain lengths had different viscosities. The higher the viscosity was, the better lubricating characteristics became. Acetyl- chemically- modified soybean oil and propionyl -chemically- modified soybean oil had high content of oxygen and strong adsorption activity to the frictional surface and can produce protection film. Therefore its lubricating characteristics were better than that of soybean oil and 150BS bright stock. The propionyl - chemically - modified soybean oil had high viscosity and the lowest pour point and could be used to blend the lubricating oils with diversified viscosity levels instead of bright stock. These blended lubricating oils prepared by propionyl - chemically - modified soybean oil and polyether had lower pour point and better tribological characteristics than that of the mineral oils of comparable viscosity level, the oxidation stability was also far better than that of mineral oil.