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Title Anti-Corrosive Paint Systems Based on Conducting Polymers
Author Petersen, Marie Louise (Materialeteknologi og -udvikling, Institut for Produktion og Ledelse, Danmarks Tekniske Universitet, DTU, DK-2800 Kgs. Lyngby, Denmark)
Supervisor Møller, Per (Materialeteknologi og -udvikling, Institut for Produktion og Ledelse, Danmarks Tekniske Universitet, DTU, DK-2800 Kgs. Lyngby, Denmark)
Institution Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
Thesis level Master's thesis
Year 2006
Abstract The corrosion protection of anti-corrosive paint systems based on conducting polymers is examined in the following four application areas: shopprimers, ballast tank protection, protection in off-shore environment and protection of aluminium. The conducting polymers used as an additive are polyaniline and polythiophene. Five possible hypotheses for the protection mechanism of conducting polymers are stated, and the aim is to examine the credibility of these hypotheses. For shopprimer applications, no improvement of the corrosion protection is established by the addition of polyaniline to a conventional shopprimer. In some of the applied shopprimers, polyaniline seems to accelerate the degradation of the paint film instead. The main explanation for these observations is a very low dispersibility of polyaniline in the paint. For protection of ballast tanks, addition of polyaniline to a conventional paint system seems to increase the resistance to cathodic disbonding. The assumption is made that polyaniline acts as an amphoteric material and reacts with the hydroxide ions, which are produced in the cathodic reaction. During this reaction, polyaniline is reduced to a non-conductive base form. For protection in off-shore environment, no improvement of the corrosion resistance is established by adding polyaniline to a conventional zinc primer. The effect of the cathodic protection is lowered, therefore polyaniline is not a suitable conductor between the zinc particles. Some positive effect is registered in the water based paint system with the addition of polythiophene in the primer. It is evaluated that a higher degree of dispersibility is the main explanation for this observation. Finally, the protective character of a conventional polyaniline containing primer is examined on aluminium. The efficiency is compared to other surface treatments that are especially designed for protection of aluminium. The results show that the polyaniline containing primer has a low adhesion to the substrate material, and the resistance to filiform corrosion is also not acceptable. The best corrosion protection is established by a conventional coating system with an anodizing pre-treatment.
Pages 69
Fulltext
Original PDF ECP_based_paint.pdf (3.85 MB)
Admin Creation date: 2007-07-19    Update date: 2011-09-27    Source: dtu    ID: 201751    Original MXD