NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

Prediction of Blistering in Coating Systems.


pdf icon Prediction of Blistering in Coating Systems. (1030 K)
Pommersheim, J. M.; Nguyen, T.

Organic Coatings for Corrosion Control. ACS Symposium Series No. 689. Proceedings. American Chemical Society. Chapter 11. April 1998, Washington, DC, Bierwagen, G. P., Editor(s), 137-150 pp, 1998.

Keywords:

coatings; blistering

Abstract:

Models based on diffusion and osmotic theory were developed for the growth of water-filled blisters at the substrate beneath organic coatings. Blister growth was considered to occur either over concentrated spots of impurity located at the point of blister initiation, or over a surface containing a uniform distribution of impurity. The solutions to both models had similar mathematical forms: the blister radius, surface area, volume, osmotic pressure, all vary directly as fractional powers of time. Exeprimental data for KHSO4 as impurity was used to test the models. Blister volume was found to vary as t0.5 (vs. t0.75 for the theory) and as Ms (vs. Ms0.75), where Ms is the mass of KHSO4. Deviations between data and theory were discussed in terms of the contact angle, blister initiation, ion concentrations within the blister, saturation, disbondment, and possible mechanical shifts.