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反气相色谱法测定Kovats及Flory-Huggins保留参数的变化以探究润滑油的氧化机理

MOSTAFA Nagy E, EISSA Elham A   

  1. Egyptian Petroleum Research Institute, Cairo, Egypt
  • 收稿日期:2006-02-20 修回日期:2006-04-15 出版日期:2006-05-30 发布日期:1987-03-25
  • 通讯作者: MOSTAFA Nagy E

Inverse Gas Chromatography Used to Study Lubricating Oil Oxidation Mechanism via Changes in Kovats and Flory-Huggins Retention Parameters

MOSTAFA Nagy E, EISSA Elham A   

  1. Egyptian Petroleum Research Institute, Cairo, Egypt
  • Received:2006-02-20 Revised:2006-04-15 Online:2006-05-30 Published:1987-03-25
  • Contact: MOSTAFA Nagy E

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摘要： Inverse gas chromatographic technique (IGC) was attempted as a new approach to follow the chemical changes that occur during lubricating base oil oxidation. Three groups of the oxidized base oils were prepared at different oxygen flow rates, periods and temperatures according to IP48 method. The corrected retention volumes (VR) were calculated for a series of selected test solutes possessing different functional groups on the oxidized base oils used as stationary phases. Kovats retention index (I), Flory-Huggins interaction parameter (κ∞1,2), and partial molar free energy of solution (ΔG∞L), were calculated for the given test solutes from their VR. The relationships between the I values and the oxidation variables were plotted and discussed. The obtained results were confirmed by potentiometric titration. The study reveals that the magnitudes of variation of I, κ∞1,2 or ΔG∞L retention parameters depend on the oxidation degree of the base oil. Large differences between the I values permit discrimination between the different oxidation steps.

关键词: Kovats retention index , lubricating base oil, oxidation, inverse gas chromatography (IGC)

Abstract: Inverse gas chromatographic technique (IGC) was attempted as a new approach to follow the chemical changes that occur during lubricating base oil oxidation. Three groups of the oxidized base oils were prepared at different oxygen flow rates, periods and temperatures according to IP48 method. The corrected retention volumes (VR) were calculated for a series of selected test solutes possessing different functional groups on the oxidized base oils used as stationary phases. Kovats retention index (I), Flory-Huggins interaction parameter (κ∞1,2), and partial molar free energy of solution (ΔG∞L), were calculated for the given test solutes from their VR. The relationships between the I values and the oxidation variables were plotted and discussed. The obtained results were confirmed by potentiometric titration. The study reveals that the magnitudes of variation of I, κ∞1,2 or ΔG∞L retention parameters depend on the oxidation degree of the base oil. Large differences between the I values permit discrimination between the different oxidation steps.

Key words: Kovats retention index , lubricating base oil, oxidation, inverse gas chromatography (IGC)