XPS of the interphase between PMMA and metals. A study of degradation and interaction

XPS was applied to PMMA layers of varying thickness in the nanometer range on gold and natural aluminium surfaces, respectively. The numerical decomposition of the core levels into the contributions from the variosus atomic bonding states reveals some peculiar features of the interphase region on the metals. First, for both metals special mechanisms of thermal destruction are deduced. On Au the splitting of complete methacrylate side groups and, even more intense, the stripping of (-O-Ch3)-units is found while on Al the side group scission is verified only. Secondly, the metals reveal different effects on the electron density in the methacrylate groups. Au appiars to be inert but the natural Al surface exerts a withdrawing effect on the electrons of both the carbon and the oxygen atoms in the side groups.