Quantitative comparison of adhesion in metal-to-plastic systems

A peel test device was used to monitor metal–polymer adhesion. This technique showed variations in the resulting force within 1%, and enabled the ranking of many systems. A change in the 50 nm-adhesion layer resulted in a variation of the fracture energy by a factor 2.3. A change of the substrate led to a change in adhesion by a factor 40. The peeling results were also combined with attenuated total reflectance Fourier transform infra-red measurements to provide qualitative insight of the bonds at the substrate surface. Differences were also visible after surface pretreatment by plasma or sputter etching with different gases, as changes in interaction bonds as well as in adhesion were observed.