Research Papers: Mixed and Boundary Lubrication

Novel One-Component Anisole- and Hydroxyl-Terminated Perfluoropolyethers for Boundary Lubrication

[+] Author and Article Information
Ao Fan

Western Digital Corporation,
5601 Great Oaks Parkway,
San Jose, CA 95119-1003
e-mail: fan.ao@wdc.com

Connie Wiita

Western Digital Corporation,
5601 Great Oaks Parkway,
San Jose, CA 95119-1003
e-mail: connie.wiita@wdc.com

Robert J. Waltman

Western Digital Corporation,
5601 Great Oaks Parkway,
San Jose, CA 95119-1003
e-mail: robert.waltman@wdc.com

1Corresponding author.

Contributed by the Tribology Division of ASME for publication in the Journal of Tribology. Manuscript received December 20, 2018; final manuscript received March 7, 2019; published online April 16, 2019. Assoc. Editor: Bart Raeymaekers.

J. Tribol 141(6), 062101 (Apr 16, 2019) (8 pages) Paper No: TRIB-18-1519; doi: 10.1115/1.4043181 History: Received December 20, 2018; Accepted March 09, 2019

The tribological properties of some novel single component perfluoropolyether (PFPE) boundary lubricants with chemically integrated mixture end groups are investigated. Chemically integrated mixture end groups composed of hydroxyl- and anisole-terminated PFPE boundary lubricant films on the –(CF2CF2CF2O)– main chain are reported. These PFPE-based boundary lubricants explore a new method by which single component PFPE lubricants with mixture end groups might be used to tailor boundary film properties instead of using physical mixtures of two or more PFPEs with different end groups. Lubricant transfer to the low-flying read/write head, head wear, and siloxane adsorption as a function of PFPE film thickness and of type are compared. Normalization of the data to the monolayer fraction instead of film thickness allows direct comparison between anisole- and hydroxyl-terminated PFPEs. Lubricant transfer to the head and head wear are independent of the functional end groups. Siloxane adsorption decreases with increasing anisole substitution of the hydroxyl groups. One-component PFPEs with mixed end groups provide a methodology by which boundary film properties could be adjusted.

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Sinha, S. K., Kawaguchi, M., Sato, T., and Kennedy, F. E., 2003, “Wear Durability Studies of Ultra-Thin Perfluoropolyether Lubricant on Magnetic Hard Disks,” Tribol. Int., 36, pp. 217–225. [CrossRef]
Raman, V., Gillis, D., and Wolter, R., 2000, “Flyability Failures Due to Organic Siloxanes at the Head/Disk Interface,” ASME J. Tribol., 122, pp. 444–449. [CrossRef]
Guo, X.-C., Raman, V., Karis, T. E., and Yao, Y. Z., 2007, “Flyability Failures Due to Siloxanes at the Head-Disk Interface Revisited,” IEEE Trans. Magn., 43, pp. 2223–2225. [CrossRef]
Yanagisawa, M., 1993, “Adsorption and Configuration of Lubricant Molecules on Overcoat Materials,” Wear 168, pp. 167–173. [CrossRef]
Waltman, R. J., Deng, H., Wang, G. J., Zhu, H., and Tyndall, G. W., 2010, “The Effect of PFPE Film Thickness and Molecular Polarity on the Pick-Up of Disk Lubricant by a Low-Flying Slider,” Tribol. Lett., 39, pp. 211–219. [CrossRef]
Khurshudov, A., and Waltman, R. J., 2001, “The Contribution of Thin PFPE Lubricants to Slider-Disk Spacing,” Tribol. Lett., 11, pp. 143–149. [CrossRef]
Waltman, R. J., Raman, V., and Burns, J., 2004, “The Contribution of Thin PFPE Lubricants to Slider-Disk Spacing. 3. Effect of Main Chain Flexibility,” Tribol. Lett., 17, pp. 239–244. [CrossRef]
Guo, X.-C., Knigge, B., Marchon, B., Waltman, R. J., Carter, M., and Burns, J., 2006, “Multidentate Functionalized Lubricant for Ultralow Head/Disk Spacing in a Disk Drive,” J. Appl. Phys., 100, p. 044306. [CrossRef]
Tsuzuki, S., 2005, “Interactions With Aromatic Rings,” Struct. Bond., 115, pp. 149–193. [CrossRef]
Waltman, R. J., Wiita, C., and Valsecchi, R., 2018, “Perfluoropolyether Boundary Lubricants Based on the Star Architecture,” Tribol. Online, 13, pp. 262–274. [CrossRef]
Toney, M. F., Mate, C. M., and Pocker, D. J., 1998, “Calibrating ESCA and Ellipsometry Measurements of Perfluoropolyether Lubricant Thickness,” IEEE Trans. Magn., 34, pp. 1774–1776. [CrossRef]
Khurshudov, A., and Waltman, R. J., 2001, “Tribology Challenges of Modern Hard Disk Drives,” Wear, 251, pp. 1124–1132. [CrossRef]
Waltman, R., and Wiita, C., 2015, “Main Chain Effects in Tetraol-Functionalized Perfluoropolyethers,” Tribol. Online, 10, pp. 262–272. [CrossRef]
Cheng, T., Zhao, B., Chao, J., Meeks, S. W., and Velidandea, V., 2000, “The Lubricant Migration Rate on the Hard Disk Surface,” Tribol. Lett., 9, pp. 181–185. [CrossRef]
Wu, S., 1982, Polymer Interface and Adhesion, Marcel Dekker, New York.
Owens, D. K., and Wendt, R. D., 1969, “Estimation of the Surface Free Energy of Polymers,” J. Appl. Polym. Sci., 13, pp. 1741–1747. [CrossRef]
Waltman, R. J., 2009, “Z-Tetraol Composition and Bonding to the Underlying Carbon Surface,” J. Colloid Interface Sci., 333, pp. 540–547. [CrossRef] [PubMed]
Waltman, R. J., and Wiita, C., 2014, “The Adsorbed Film Structure of End-Functionalized Poly(Perfluoro-n-Propylene Oxide),” Tribol. Online, 9, pp. 113–120. [CrossRef]
Akamatsu, N., and Ohtani, T., 2002, “Study of the Adsorption of Siloxane and Hydrocarbon Contaminants Onto the Surfaces at the Head/Disk Interface of a Hard Disk Drive by Thermal Desorption Spectroscopy,” Tribol. Lett., 13, pp. 15–20. [CrossRef]


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Fig. 1

The chemical structures of (a) D-2OH, (b) D-3OH, (c) D-4OH, (d) DART-1S, and (e) DART-2

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Fig. 2

The film thickness correlation between the PFPE IR band maximum and ESCA for the PFPEs used in these experiments

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Fig. 3

The experimental chamber used to expose disks to siloxanes using Taica rubber as the source. The infrared spectra compare authentic polydimethylsiloxane and the outgassing components from the Taica gel that decorate the disk surface.

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Fig. 4

The (a) dispersive and (b) polar components of the surface energy as a function of film thickness for DART-1S and DART-2 on an amorphous carbon surface

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Fig. 5

The dispersive, polar, and total disjoining pressure as a function of film thickness for (a) DART-1S and (b) DART-2

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Fig. 6

Ellipsometric images of the disk surface as a function of film thickness for DART-1S and DART-2

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Fig. 7

Changes in the film thickness as a function of burnish passes for (a) DART-1S and (b) DART-2

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Fig. 8

Summary plot of the average monolayer film thickness for D-4OH, DART-1S, and DART-2 as a function of number average molecular weight

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Fig. 9

Lubricant pick-up as a function of PFPE: (a) film thickness, (b) disjoining pressure, and (c) monolayer fraction

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Fig. 10

Head wear rate as a function of PFPE: (a) film thickness and (b) monolayer fraction

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Fig. 11

The bonded fraction for 10–11 Å PFPE films as a function of time under ambient storage

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Fig. 12

The adsorbed siloxane counts (SiC3H9) as a function of PFPE: (a) film thickness and (b) monolayer fraction



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