[article]
| Titre : |
Study of the attack of acidic solutions on melamine-acrylic basecoat/clearcoat paint systems |
| Type de document : |
texte imprimé |
| Auteurs : |
W. R. Rodgers, Auteur ; D. P. Garner, Auteur ; G. D. Cheever, Auteur |
| Année de publication : |
1998 |
| Article en page(s) : |
p. 83-95 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Automotile -- Peinture -- Détérioration
Couches minces
MélamineLa mélamine, de nom chimique 1,3,5-triazine-2,4,6-triamine, est parfois dénommée cyanuramide ou cyanurotriamine. Sa formule brute est C3H6N6.
Les "résines mélamine-formaldéhyde" ou "mélamine-formol" (sigle MF) sont appelées "mélamine" dans le langage courant. Elles font partie de la famille des aminoplastes qui regroupe des résines thermodurcissables aminées, issues d'un comonomère tel l'urée ou la mélamine, parfois le thiocarbamide, le cyanamide hydrogène ou le dicyandiamide ; le second comonomère étant le formaldéhyde.
Pluies acides
Polyacryliques
Primaire (revêtement)
Revêtements -- Analyse
Vernis -- Analyse
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
The extent of penetration of an acidic solution into a melamine-acrylic coating, the bulk changes in the thermal properties of the coating, and the chemistry and kinetics of acid degradation were investigated. Fluorescent microscopy experiments showed that significant penetration of the clearcoat occurs rapidly with acidic solutions. Thermal analysis of a matrix of samples exposed to a variety of conditions showed that significant differences occurred as a function of time, temperature, and acid concentration. Infrared analysis showed unreacted excess alkoxymethyl melamine was hydrolyzed first, followed by the hydrolysis of the crosslinks. Acidic solutions are able to penetrate the coating in a short time. Once in the coating, chemical reactions occur which result in degradation of the crosslinked network causing a change in the thermal properties and the appearance of the coating materials. The reaction is hydrolysis of the crosslinks followed by either destruction or leaching of the crosslinking material. |
| Note de contenu : |
- EXPERIMENTAL : Panel preparation - Light microscopy - Fluorescent microscopy - Profilometry - Extended period immersion experiments - Differential scanning calorimetry analysis - Infrared spectroscopy
- RESULTS AND DISCUSSION : Spotting exposure experiments - Constant concentration exposure experiments |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=17963 |
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 70, N° 877 (02/1998) . - p. 83-95
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Study of the attack of acidic solutions on melamine-acrylic basecoat/clearcoat paint systems in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 70, N° 877 (02/1998)
