The delamination of polymeric coatings from electrogalvanised steel - a mechanistic approach. Part 1: delamination from a defect with intact zinc layer

摘要

The basic mechanism of the cathodic delamination of polymer films from zinc-coated steel starting from a defect with an intact zinc layer has been derived. Scanning Kelvinprobe and ESCA measurements have been carried out with a very simple model system. The delamin- ation is presented as the formation of a galvanic element between the active defect and the delamination front with electrons and cations being transported to the local cathode. The oxygen reduction in the delaminated area leads to an alkalinisation of the zinc/polymer in- terface resulting in a significant growth of the oxide layer.