Studies on polymer-metal interfaces, 4^a: Effect of substituent of polymethacrylate on the interfacial characteristics between polymethacrylates and copper

The interfacial characteristics between polymethacrylates and copper were investigated. The adhesion strength between poly(methyl methacrylate) (PMMA)/copper was the highest, while that between poly(ethyl methacrylate) (PEMA)/copper was the lowest among the four polymethacrylates/copper systems, i.e., PMMA/copper, PEMA/copper, poly(n-butyl methacrylate) (PnBMA)/copper, and poly(i-butyl methacrylate) (PiBMA)/copper. Analysis of X-ray photoelectron spectroscopy (XPS) shows that the carbonyl functional groups in polymethacrylate interact specifically with copper and the degree of specific interaction decreases in the order of PMMA/copper > PnBMA/copper ≥ PiBMA/copper > PEMA/copper. Results from reflection-absorption infrared (RA-IR) spectroscopy indicate that the adsorption behavior of polymethacrylate is closely related to the orientation of the carbonyl group upon the copper surface and that the carbonyl group is more perpendicularly oriented near the interface due to the specific interaction with the copper surface.