Novel Approaches for Characterizing the Delamination Resistance of Organic Coatings

Based on the results of the pioneering work by Stratmann et al. [1, 2, 3, 4], it may be assumed that corrosion driven delamination of an organic coating should be mainly determined by a few key properties, such as its barrier properties against water, ions and oxygen, its resistance against cation diffusion/migration along its interface to the metal, its resistance against oxygen reduction at this interface and its resistance against radicals produced as side products of this oxygen reduction reaction. Especially the two last properties should define highly delamination resistant coatings. However, so far it was not possible to obtain information about the correlated reaction rates at the buried interface between the organic coating and the metal. Recently, we have developed a novel experimental approach that direct provides information about the oxygen reduction rate at the buried interface as well as on the interfacial degradation resistance [5]. The potential of this technique will be discussed for the case of selected examples. [1] A. Leng, H. Streckel, M. Stratmann, Corros. Sci. 41 (1999) 547-578 [2] A. Leng, H. Streckel, M. Stratmann, Corros. Sci. 41 (1999) 579-597 [3] A. Leng, H. Streckel, K. Hofmann, M. Stratmann, Corros. Sci. 41 (1999) 599-620 [4] M. Rohwerder, M. Stratmann, MRS Bulletin 24 (1999) 43-47 [5] V. Dandapani, T.H.Tran, A. Bashir, S. Evers. M. Rohwerder, Electrochim. Acta 189 (2016) 111-117