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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Autores principales:	Paul H. Kasai, Masako Ikegami
Formato:	article
Lenguaje:	EN
Publicado:	Japanese Society of Tribologists 2010
Materias:	magnetic disks disk lubricants hamr perfluoropolyethers z-dol z-tetraol nmr Physics QC1-999 Engineering (General). Civil engineering (General) TA1-2040 Mechanical engineering and machinery TJ1-1570 Chemistry QD1-999
Acceso en línea:	https://doaj.org/article/1858fadbb3dd42b88025633c13aea9d7
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id	oai:doaj.org-article:1858fadbb3dd42b88025633c13aea9d7
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spelling	oai:doaj.org-article:1858fadbb3dd42b88025633c13aea9d72021-11-05T09:26:40ZOxidation of Disk Lubricants: an NMR Study1881-219810.2474/trol.5.271https://doaj.org/article/1858fadbb3dd42b88025633c13aea9d72010-11-01T00:00:00Zhttps://www.jstage.jst.go.jp/article/trol/5/6/5_6_271/_pdf/-char/enhttps://doaj.org/toc/1881-2198Z-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 &sim; 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.Paul H. KasaiMasako IkegamiJapanese Society of Tribologistsarticlemagnetic disksdisk lubricantshamrperfluoropolyethersz-dolz-tetraolnmrPhysicsQC1-999Engineering (General). Civil engineering (General)TA1-2040Mechanical engineering and machineryTJ1-1570ChemistryQD1-999ENTribology Online, Vol 5, Iss 6, Pp 271-283 (2010)
institution	DOAJ
collection	DOAJ
language	EN
topic	magnetic disks disk lubricants hamr perfluoropolyethers z-dol z-tetraol nmr Physics QC1-999 Engineering (General). Civil engineering (General) TA1-2040 Mechanical engineering and machinery TJ1-1570 Chemistry QD1-999
spellingShingle	magnetic disks disk lubricants hamr perfluoropolyethers z-dol z-tetraol nmr Physics QC1-999 Engineering (General). Civil engineering (General) TA1-2040 Mechanical engineering and machinery TJ1-1570 Chemistry QD1-999 Paul H. Kasai Masako Ikegami Oxidation of Disk Lubricants: an NMR Study
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 &sim; 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.
format	article
author	Paul H. Kasai Masako Ikegami
author_facet	Paul H. Kasai Masako Ikegami
author_sort	Paul H. Kasai
title	Oxidation of Disk Lubricants: an NMR Study
title_short	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_sort	oxidation of disk lubricants: an nmr study
publisher	Japanese Society of Tribologists
publishDate	2010
url	https://doaj.org/article/1858fadbb3dd42b88025633c13aea9d7
work_keys_str_mv	AT paulhkasai oxidationofdisklubricantsannmrstudy AT masakoikegami oxidationofdisklubricantsannmrstudy
_version_	1718444332692799488

Oxidation of Disk Lubricants: an NMR Study

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