Titre : |
Novel CNSL-based waterborne Zn-rich primer systems for protective coatings |
Type de document : |
texte imprimé |
Auteurs : |
Hong Xu, Auteur ; Fernanda Tavares, Auteur ; Anbu Natesh, Auteur ; Jing Li, Auteur |
Année de publication : |
2018 |
Article en page(s) : |
p. 34-42 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Anticorrosifs Anticorrosion Application directe sur le métal Brillance (optique) Cardanol Epoxydes Essais d'adhésion Essais de brouillard salin Formulation (Génie chimique) Métaux -- Revêtements protecteurs Noix de cajou et constituants Phénalkamines Polyuréthanes Primaire (revêtement) Réticulants Revêtements -- Finition Revêtements -- Propriétés mécaniques Revêtements bi-composant Revêtements en phase aqueuse Rhéologie Zinc
|
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Low-VOC waterborne (WB) Zn-rich primers and high performance WB epoxy primers have been developed based on novel Cashew Nutshell Liquid (CNSL)-derived curing agents for industrial and protective coating applications. These unique WB phenalkamines were synthesized from a natural, non food chain and renewable biomaterial and could help formulate WB primer systems that meet stricter volatile organic compound (VOC) regulations as well as high performance requirerments.
This article presents the latest performance studies of new phenalkamine-based WB Zn-rich primers and epoxy primers, and discusses the challenges associated with such formulations.
New 2K WB Zn-rich primers were formulated with a water-free phenalkamine curing agent. The study results showed the WB Zn-rich primers had good compatibility with various commercially available solid epoxy dispersions and delivered good cure and mechanical properties ; importantly, those WB Zn-rich primers provided superb adhesion to both metal substrates and commercial polyurethane (PU) topcoats without the use of adhesion promoters. Excellent corrosion protection and good resistance to undercutting of the scribe were observed after 3000-h Q-Fog exposure.
Additionally, newly developed WB high performance primers based on zero-VOC WB phenalkamines were evaluated either in combination with WB Zn-rich primers or by being directly applied over metal substrates was found that those WB epoxy primers could enhance corrosion protection as mid-coats to WB Zn-rich primers ; when being used direct-to-metal, WB epoxy primers also exhibited good mechanical and adhesion properties that benefited the overall anticorrosion performances. |
Note de contenu : |
- Part I : Waterborne (WB) Zn-rich primer study
- Part II : Waterborne (WB) mid-coat systems based on new WB-C curing agent
- Part III : Wet-on-wet properties
- FIGURES : 1. Cashew apple and nutshell - 2. Average cardanol structure - 3. Example of phenalkamine structure - 4. Panel images of cross-hatch adhesion tests - 5. Panel images after 120h salt spray exposure - 6. Panel images after 4000-h salt spray exposure - 7. Panel images after 1200-h salt spray exposure - 8. Panel images after 2400-h salt spray exposure (surface rusts were removed via scratch pad) - 9. Panel images after 2300-h salt spray exposure (WB Zn-rich primer systems topcoated with a red iron oxide mid-coat) - 10. Panel images after scribe and wet adhesion testing - 11. Mixing viscosity changes as a function of the percentage of added water - 12. Linear dry time of various systems based on WB-C - 13. Panel images of resin 1+WB-C clear coating-system after 1200-h salt spray exposure - 14. Panel images of MC#1 and MC#2 systems after 271 and 767-h salt spray exposure - 15. Panel image of WB Zn-rich#4 primer system topcoated with MC#2 mid-coat primer after 1685-h salt spray exposure - 16. Photo images of the panels after wet-on-wet adhesion tests
- TABLES : 1. Waterborne curing agents : typical properties - 2. Typical properties of solid epoxy dispersion resins - 3. WB Zn-rich primer formulations by using WB-A curing agent - 4. Mechanical properties of WB Zn-Rich primers - 5. WB mid-coat formulations based on WB-C - 6. Adhesion and anticorrosion performances of MC#2 systems as a function of mixing times - 7. Mechanical and adhesion properties of MC#2 - 8. Gloss comparison |
En ligne : |
https://drive.google.com/file/d/1QsQ8l4uOx13cFvlKXZElv8uh5js2daAr/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30518 |
in COATINGS TECH > Vol. 15, N° 4 (04/2018) . - p. 34-42