Journal ArticleDOI
Perfluoropolyethers: intramolecular disproportionation
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TLDR
In this paper, the thermal degradation of commercial perfluoropolyethers (Fomblin Z and Y, Krytox, and Demnum) and PFPEO (perfluoropoly(ethylene oxide)) in the presence of Lewis acids (metal oxides and halides) was examined.Abstract:
Thermal degradation of commercial perfluoropolyethers (Fomblin Z and Y, Krytox, and Demnum) and PFPEO (perfluoropoly(ethylene oxide)) in the presence of Lewis acids (metal oxides and halides) was examined. It is shown that the degradation is dominated by the intramolecular disproportionation process of the following scheme RCF 2 OCF 2 (CH 2 ) 3 OR → RCOF + CF 3 (CH 2 ) 3 OR. The reaction occurs when the two oxygen atoms flanking a monomer unit of polyether chains interact with a Lewis acid site(s). The differentail charges induced at the carbons immediately outside and inside the unit cause a fluorine transdfer and effect the disproportionation processread more
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Journal ArticleDOI
Laser-Induced Short Time Scale Thermal Chemistry of Perfluoropolyether Lubricant Films
TL;DR: In this article, the authors investigate the effect of heating a perfluoropolyether lubricant film in a localized area for relatively short time periods using laser irradiation versus conventional oven heating.
Journal ArticleDOI
The Effect of Additives on the Wear Behavior of Bearing Steels with RfO(CFfO)x(CF2CF2O)y(CF2CF2CF2O)zRf Perfluoropolyalkylether Fluids
Lois J. Gschwender,Shashi K. Sharma,Carl E. Snyder,Larry S. Helmick,George W. Fultz,Bruce Schreiber +5 more
TL;DR: In this paper, the effect of humidity on wear was observed with a four-ball tribometer using the same base fluid in an oxygen-deficient environment with 52100 bearing steel.
Journal ArticleDOI
Friction–wear behavior and tribochemical reactions of different ceramics in HFC-134a gas
TL;DR: In this article, the friction and wear properties of the ionic ceramics Al 2 O 3 and ZrO 2, and the covalent ceramic Si 3 N 4 and SiC were investigated using a ball-on-disk type tribometer using X-ray photoelectron spectroscopy (XPS).
Journal ArticleDOI
Highly durable hydrophobicity in simulated space environment
TL;DR: By infusing perfluoropolyether lubricating liquids into hierarchical micro- and nano-structures, a highly durable hydrophobic material was obtained for resisting low earth orbit space irradiations such as atom oxygen, ultraviolet, proton, and electron irradiations as discussed by the authors.
Journal ArticleDOI
Electron beam induced degradation of polyperfluorinated ethers: -(CF(CF3)-CF2-O)n-, for n = 4, 8 and 50
TL;DR: In this paper, the efficiency for gas evolution decreases with increasing number of monomer units in the polymer and the G values range from 0.1 to 3, depending upon the gas product and n.
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