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Evaluation of boundary-enhancement additives for perfluoropolyethers
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Lin, Tzuhn-Yuan Kawa, Hajimu Jones Jr., William R. Herrera-Fierro, Pilar Shogrin, Bradley A. |
| Copyright Year | 1996 |
| Description | Six 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. |
| File Size | 1023375 |
| Page Count | 24 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19970010386 |
| Archival Resource Key | ark:/13960/t28964k1z |
| Language | English |
| Publisher Date | 1996-12-01 |
| Access Restriction | Open |
| Subject Keyword | Nonmetallic Materials Sulfites Perfluoro Compounds Infrared Spectroscopy Additives Wear Amorphous Materials Boundary Lubrication Polyether Resins Raman Spectroscopy Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
