The concentration of oleic acid as an additive at elastohydrodynamic lubrication (EHL) was investigated by means of in-situ observation with micro Fourier Transform infrared Spectrometer (FTIR). lt was found that the concentration of additive at the Hertzian contact region depended on the properties of the base oil. When poly-α-olefin(PAO) with nonpolarity was used as base oil，the concentration at the Hertzian contact
region decreased to a half of the original lubricant. On the other hand，it did not change in the base oil of polybutyleneglycol (PBG) or polypropyleneglycol (PPG) which has polarity. The results indicate that oleic
acid was introduced into the Herzian contact region by a polar interaction with ether oils which was observed from IR spectra. When Polyphenylether (5P4E) was used as base oil，the concentration did not change，although there is no strong interaction between oleic acid and 5P4E. lt can be explained that 5P4E with high viscosity-pressure coefficient solidified at the Herzian contact region and caught oleic acid. The IR peak of stretching mode of carbonyl group in oleic acid indicated to be a dimer and was shifted to lower wavenumber at Herzian contact region. This result means the stabilization of the hydrogen bond of the
dimmer under high pressure.
出版者
日本トライボロジー学会
その他のタイトル
The Interaction between Oleic Acid and Base Oils at Elastohydrodynamic Lubrication
弾性流体潤滑下におけるオレイン酸と基油との相互作用
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