Oxidation of Disk Lubricants: an NMR Study
Z-dol and Z-tetraol represent most often used disk lubricants. So that we would be better able to design lubricants of higher thermal stability (for Heat-Assisted-Magnetic-Recording application), detailed analysis of thermally induced oxidation processes of Z-dol and Z-tetraol were performed. Sampl...
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| Format: | Article |
| Language: | English |
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Japanese Society of Tribologists
2010-11-01
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| Series: | Tribology Online |
| Subjects: | |
| Online Access: | https://www.jstage.jst.go.jp/article/trol/5/6/5_6_271/_pdf/-char/en |
| _version_ | 1818568724326645760 |
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| author | Paul H. Kasai Masako Ikegami |
| author_facet | Paul H. Kasai Masako Ikegami |
| author_sort | Paul H. Kasai |
| collection | DOAJ |
| description | Z-dol and Z-tetraol represent most often used disk lubricants. So that we would be better able to design lubricants of higher thermal stability (for Heat-Assisted-Magnetic-Recording application), detailed analysis of thermally induced oxidation processes of Z-dol and Z-tetraol were performed. Samples were heated in a thin-film configuration where facile infusion of oxygen occurred and were examined by F-19 and C-13 NMR. Z-dol was found to be stable in the 150 ∼ 200 °C temperature range. In the same temperature range Z-tetraol was found to undergo either (1) the well known step-wise oxidation of primary alcohol (alcohol → aldehyde → acid) or (2) direct conversion to Z-dol. The latter process is initiated by a base-catalyzed step whereby the end-group Z-O-CF2-CH2-O-CH2-CH(-OH)-CH2-OH converts to an aldehyde, Z-O-CF2-CH2-O-CH2-CH( = O), and CH3OH. Z-dol results upon oxidation of the aldehyde yielding Z-O-CF2-CH2-OH, CH2 = O and CO2. It was found that substitution of the terminal OH with a phenoxy unit suppressed these decomposition processes. Z-tetraol lubricant molecular chains that became bound to the carbon overcoat at their termini are also protected from these oxidation processes. Thus for HAMR application, a combination of lubricants bonded to the carbon overcoat at their termini and mobile lubricants possessing phenoxy groups at their termini may be the best possible system based on perfluoropolyether lubricants. |
| first_indexed | 2024-12-14T06:38:51Z |
| format | Article |
| id | doaj.art-1858fadbb3dd42b88025633c13aea9d7 |
| institution | Directory Open Access Journal |
| issn | 1881-2198 |
| language | English |
| last_indexed | 2024-12-14T06:38:51Z |
| publishDate | 2010-11-01 |
| publisher | Japanese Society of Tribologists |
| record_format | Article |
| series | Tribology Online |
| spelling | doaj.art-1858fadbb3dd42b88025633c13aea9d72022-12-21T23:13:17ZengJapanese Society of TribologistsTribology Online1881-21982010-11-015627128310.2474/trol.5.271trolOxidation of Disk Lubricants: an NMR StudyPaul H. Kasai0Masako Ikegami1MORESCO CorporationMORESCO CorporationZ-dol and Z-tetraol represent most often used disk lubricants. So that we would be better able to design lubricants of higher thermal stability (for Heat-Assisted-Magnetic-Recording application), detailed analysis of thermally induced oxidation processes of Z-dol and Z-tetraol were performed. Samples were heated in a thin-film configuration where facile infusion of oxygen occurred and were examined by F-19 and C-13 NMR. Z-dol was found to be stable in the 150 ∼ 200 °C temperature range. In the same temperature range Z-tetraol was found to undergo either (1) the well known step-wise oxidation of primary alcohol (alcohol → aldehyde → acid) or (2) direct conversion to Z-dol. The latter process is initiated by a base-catalyzed step whereby the end-group Z-O-CF2-CH2-O-CH2-CH(-OH)-CH2-OH converts to an aldehyde, Z-O-CF2-CH2-O-CH2-CH( = O), and CH3OH. Z-dol results upon oxidation of the aldehyde yielding Z-O-CF2-CH2-OH, CH2 = O and CO2. It was found that substitution of the terminal OH with a phenoxy unit suppressed these decomposition processes. Z-tetraol lubricant molecular chains that became bound to the carbon overcoat at their termini are also protected from these oxidation processes. Thus for HAMR application, a combination of lubricants bonded to the carbon overcoat at their termini and mobile lubricants possessing phenoxy groups at their termini may be the best possible system based on perfluoropolyether lubricants.https://www.jstage.jst.go.jp/article/trol/5/6/5_6_271/_pdf/-char/enmagnetic disksdisk lubricantshamrperfluoropolyethersz-dolz-tetraolnmr |
| spellingShingle | Paul H. Kasai Masako Ikegami Oxidation of Disk Lubricants: an NMR Study Tribology Online magnetic disks disk lubricants hamr perfluoropolyethers z-dol z-tetraol nmr |
| title | Oxidation of Disk Lubricants: an NMR Study |
| title_full | Oxidation of Disk Lubricants: an NMR Study |
| title_fullStr | Oxidation of Disk Lubricants: an NMR Study |
| title_full_unstemmed | Oxidation of Disk Lubricants: an NMR Study |
| title_short | Oxidation of Disk Lubricants: an NMR Study |
| title_sort | oxidation of disk lubricants an nmr study |
| topic | magnetic disks disk lubricants hamr perfluoropolyethers z-dol z-tetraol nmr |
| url | https://www.jstage.jst.go.jp/article/trol/5/6/5_6_271/_pdf/-char/en |
| work_keys_str_mv | AT paulhkasai oxidationofdisklubricantsannmrstudy AT masakoikegami oxidationofdisklubricantsannmrstudy |