The Effect of UV Stabilizer on the Photo Degradation of Perfluoropolyether Lubricants Used in Hard Disk

Abstract

Ultraviolet (UV) light exposure can lead to photo degradation of perfluoropolyether (PFPE) lubricants, resulting in a change of their physical properties. In this article, 2,3,4,5,6-pentafluorobenzophenone was used as an ultraviolet stabilizer (UVS) to slow down the photo degradation of PFPE. PFPE/UVS mixtures were exposed to UV light and the mechanism of photo degradation was studied with nuclear magnetic resonance (NMR). Small amounts of UVS (less than 0.3 wt.%) were found to effectively stabilize both UV photo degradation at the main chain and the end chain of PFPE without affecting the thermal stability of PFPE. However, phase separation of PFPE and UVS was found to occur due to chemical incompatibility of the components.