• Title/Summary/Keyword: Lewis acid disproportionation

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Lewis Acid Degradation Characteristics of Perfluoropolyethers Derivatives (퍼프로로폴리에테르 유도체의 루이스 산 분해특성)

  • Chun, Sang-Wook;Kang, Ho-Jong
    • Polymer(Korea)
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    • v.38 no.5
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    • pp.650-655
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    • 2014
  • The degradation characteristics of perfluoropolyether (PFPE) derivatives currently being used as computer hard disk lubricants have been investigated. Especially, we considered the effects of end group on degradation behavior of PFPE derivatives. It was found that the degradation of PFPE derivatives in the presence of $Al_2O_3$ involves two degradation mechanisms such as thermal degradation and Lewis acid disproportionation by $AlF_3$ which was mainly formed by oxide-to-halide reaction between $Al_2O_3$ and the degraded PFPE. The end groups were strongly related to Lewis acid disproportionation of PFPE derivatives, and it is due to the difference of electron donating ability in the each end groups. Even if PFPE derivatives have same repeating unit in the main chain, Lewis acid disproportionation was prohibited by higher electron donating ability by the end group which caused the high electron density at the acetal group in the repeating unit.