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
A computer modelling study on the interaction of -(CF2CF2O)- polyperfluorinated ethers with Lewis acid sites: perfluorodiethyl ether
TL;DR: In this paper, a trans-trans conformation of perfluorodiethyl ether (PFDEE) was used to investigate the Lewis acid-base interactions between polyperfluorinated ethers and Lewis acid sites.
Journal ArticleDOI
A review of the effect of metals on the thermo‐oxidative stability of perfluoropolyalkylether lubricants
TL;DR: The structural attributes and degradation mechanisms for Fomblin Z, DemnumTM, and Krytox® type perfluoropolyalkylether (PFPAE) fluids both in the presence and absence of metals/alloys are reviewed in this article.
Journal ArticleDOI
Behavior of High Temperature Lubricants in a Pressure Differential Scanning Calorimeter
TL;DR: In this article, the effects of pressure and diffusion restriction on PDSC data were investigated for several classes of high temperature lubricants, including polyphenylethers, polyphenylthioethers, cyclophosphazenes, and perfluoroalkylthers.
The Effect of ODC-Free Cleaning Techniques on Bearing Lifetimes in the Parched Elastohydrodynamic Regime
TL;DR: In this paper, a parched elastohydrodynamic rig was used to determine relative bearing lifetimes as a function of cleaning procedures in a series of accelerated tests, and two ODC-free cleaning procedures (super critical CO2 and ultraviolet-ozone) were compared to a CFC-113 control.
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