[article]
| Titre : |
Interfaces of polyphenyletheretherketone (PEEK) and polyphenylene sulfide (PPS) coated zinc phosphated steels after heating-cooling cycles in a wet, harsh environment |
| Type de document : |
texte imprimé |
| Auteurs : |
T. Sugama, Auteur ; N. Carciello, Auteur |
| Année de publication : |
1994 |
| Article en page(s) : |
p. 43-54 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Acier L'acier est un alliage métallique utilisé dans les domaines de la construction métallique et de la construction mécanique.
L'acier est constitué d'au moins deux éléments, le fer, très majoritaire, et le carbone, dans des proportions comprises entre 0,02 % et 2 % en masse1.
C'est essentiellement la teneur en carbone qui confère à l'alliage les propriétés du métal qu'on appelle "acier". Il existe d’autres métaux à base de fer qui ne sont pas des aciers comme les fontes et les ferronickels par exemple.
Adhésion
Anticorrosion
Atmosphère humide
Chimie des surfaces
Contraintes thermiques
Délaminage
Essais accélérés (technologie)
Métaux -- Revêtements protecteurs
Phosphate de zinc
Polyéther éther cétone
Polysulfures de phénylène
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
To evaluate the ability of polyphenyletheretherketone (PEEK) and polyphenylene sulfide (PPS) thermoplastic coatings that protect zinc phosphate (Zn.Ph)-treated steels from corrosion in a wet, harsh environment (1.0 wt% H2SO4, 3.0 wt% NaCl, and 96.0% wt% water at temperatures from 25° to 200°C), we exposed them in autoclave to attempt heating-cooling cyclic fatigue tests (1 cycle - 12 hr at 200°C + 12 hr at 25°C) up to 90 times. Although no changes in appearance were seen in the PEEK specimens after 60 cycles, extending the cycles to 90 caused the delamination of the coating film from the Zn.Ph. The major reason for this delamination was the degradation of the PEEK polymer caused by its hydrothermal-catalyzed esterification. In the PPS-coating systems, chemical reactions at the interfaces between the PPS and Zn and Fe in the Zn.Ph layer during cycling led to the formation of ZnS and FeS reaction products, which enhanced the Zn.Ph-to-PPS adhesive bond; correspondingly, there were no signs of peeling and separation of the coating after 90 cycles. In addition, because these intermediate reaction products are insoluble at high pH, they minimized the rate of delamination of the PPS coating caused by the cathodic reaction, H2O + 1/2 O2 + 2e- ' 2OH-, at the corrosion side of a defect in the film. In contrast, PEEK coatings containing non-reactive Zn.Ph underwent cathodic delamination, because of the susceptibility of Zn.Ph to alkali dissolution. Thus, we believe that combined layers of PPS and Zn.Ph provide great protection to steels in a harsh environment with temperatures up to 200°C. |
| Note de contenu : |
- EXPERIMENTAL METHODS : Materials - Measurements
- RESULTS AND DISCUSSION : PEEK coating systems - PPS coating system - Cathodic delamination |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18727 |
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 66, N° 838 (11/1994) . - p. 43-54
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Interfaces of polyphenyletheretherketone (PEEK) and polyphenylene sulfide (PPS) coated zinc phosphated steels after heating-cooling cycles in a wet, harsh environment in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 66, N° 838 (11/1994)
