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Determination Of The Oxidative Stability Of Perfluoropolyalkyl Ethers And Correlation With Chemical Structure, Larry S. Helmick, William R. Jones Jr
Determination Of The Oxidative Stability Of Perfluoropolyalkyl Ethers And Correlation With Chemical Structure, Larry S. Helmick, William R. Jones Jr
Science and Mathematics Faculty Publications
The oxidative stabilities of several perfluoropolyalkyl ethers (PFPAE) with related chemical structures were determined by thermal gravimetric analysis and correlated with their chemical structures. These results show that oxidative stability increases as the number of difluoroformal groups decreases and as trifluoromethyl substituents are added. They are also consistent with a recently proposed intramolecular disproportionation reaction mechanism involving coordination of successive ether oxygens to a Lewis acid. Since polytetrafluoroethylene contains no oxygen, it provides an indication of the upper limit to oxidative stability of PFPAE fluids. These results also show that oxidative decomposition of PFPAE fluids requires the presence of an …
Determination Of The Thermal Stability Of Perfluoropolyalkyl Ethers By Tensimetry, Larry S. Helmick, William R. Jones Jr
Determination Of The Thermal Stability Of Perfluoropolyalkyl Ethers By Tensimetry, Larry S. Helmick, William R. Jones Jr
Science and Mathematics Faculty Publications
The thermal decomposition temperatures of several perfluoropolyalkyl ether fluids were determined with a computerized tensimeter. In general, the decomposition temperatures of the commercial fluids were all similar and significantly higher than those for noncommercial fluids. Correlation of the decomposition temperatures with the molecular structures of the primary components of the commercial fluids revealed that the stability of the fluids was not affected by carbon chain length, branching, or adjacent difluoroformal groups. Instead, stability was limited by the presence of small quantities of thermally unstable material and/or chlorine-containing material arising from the use of chlorine containing solvents during synthesis. Finally, correlation …