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Evaluation of Boundary-Enhancement Additives for PerfluoropolyethersSix additives were synthesized and evaluated as boundary lubrication enhancers for perfluoropolyethers. These additives included a phosphonate, a thiophosphonate, a beta-diketone, a benzothiazole, an amide and a sulfite. These additives were evaluated in a vacuum four-ball apparatus, at a one weight percent concentration in a perfluoropolyether based on hexafluoropropene oxide. Tests were performed in vacuum (less than 5.0 x 10(exp 6) Torr), at room temperature (approx. 23 C), at an initial Hertzian stress of 3.5 GPa (200N load), and a sliding velocity of 28.8 mm/sec (100 rpm). Infrared (IR) and Raman spectroscopies were used to analyze the 440 C specimens after testing. Wear rates for each formulation were determined from the slope of wear volume as a function of sliding distance. All additives yielded reductions in mean wear rates of at least 55 percent, with the exception of the benzothiazole which had no effect. Two of the additives, an amide and a sulfite, reduced the mean wear rate by at least 80 percent. IR and Raman analysis indicated the severity of wear can be correlated to the amount of surface fluorinated polymeric acid species (R(sub f)COOH) and amorphous carbon, in and around the wear scar.
Document ID
19970010386
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Shogrin, Bradley A.
(Case Western Reserve Univ. Cleveland, OH United States)
Jones, William R. , Jr.
(NASA Lewis Research Center Cleveland, OH United States)
Herrera-Fierro, Pilar
(Ohio Aerospace Inst. Brook Park, OH United States)
Lin, Tzuhn-Yuan
(Exfluor Research Corp. Austin, TX United States)
Kawa, Hajimu
(Exfluor Research Corp. Austin, TX United States)
Date Acquired
September 6, 2013
Publication Date
December 1, 1996
Subject Category
Nonmetallic Materials
Report/Patent Number
NASA-TM-107393
NAS 1.15:107393
E-10594
Meeting Information
Meeting: 1997 Tribology Conference
Location: London
Country: United Kingdom
Start Date: September 8, 1997
End Date: September 12, 1997
Sponsors: Society of Tribologists and Lubrication Engineers, American Society of Mechanical Engineers
Accession Number
97N15607
Funding Number(s)
PROJECT: RTOP 225-00-00
CONTRACT_GRANT: NAS3-27285
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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