Molecular orbital simulations on the degradation of lubricant for magneticdisks

Molecular orbital simulations on a formation of a C=O group, which was dete cted as a product of triboreaction in a perfluoropoly(ether) (PFPE) layer i n the wear test on a magnetic recording disk, were carried out. Catalytic a nd electron-induced processes were simulated to stimulate the formation of the C=O end group. Estimated activation energies for both processes were hi gher than those for other degradation paths, such as the unzipping reaction . These estimated energies gave a reason for the low yields of the C=O grou p under a moderate load. Simulations on the interaction of a PFPE with a CF O end group and Al(OH)(2)(+) as an active site model on the material surfac e suggested a strong interaction compared to the case of a PFPE with a CFB end group. From these simulations it was expected that a PFPE with a CFO en d group would tend to mask selectively active sites on the surface and form a lubricative molecular layer. Experimental results on the frictional beha vior of a photochemically formed polymer film of perfluoromethylene oxide w ith a CFO end group suggested the ability to form the lubricative molecular layer on the sliding surface.