[article]
Titre : |
Multiscale physical characterization of an outdoor-exposed polymeric coating system |
Type de document : |
texte imprimé |
Auteurs : |
Xiaohong Gu, Auteur ; Li-Piin Sung, Auteur ; Bouchra Kidah, Auteur ; Mounina Oudina, Auteur ; Cyril Clerici, Auteur ; Hu Haiqing, Auteur ; Debbie Stanley, Auteur ; Walter E. Byrd, Auteur ; Jerry Y. C. Jean, Auteur ; Tinh Nguyen, Auteur ; Jonathan W. Martin, Auteur |
Année de publication : |
2009 |
Article en page(s) : |
p. 67-79 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Analyse multiéchelle Brillance (optique) Caractérisation Dispersion rotatoire (optique) Microscopie à force atomique Microscopie confocale Morphologie (matériaux) Optique Revêtements protecteurs Rugosité
|
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Surface topography and gloss are two related properties affecting the appearance of a polymeric coating system. Upon exposure to ultraviolet (UV) radiation, the surface topography of a coating becomes more pronounced and, correspondingly, its gloss generally decreases. However, the surface factors affecting gloss and appearance are difficult to ascertain. In this article, atomic force microscopy (AFM) and laser scanning confocal microscopy (LSCM) measurements have been performed on an amine-cured epoxy coating system exposed to outdoor environments in Gaithersburg, Maryland. The formation of the protuberances is observed at the early degradation stages, followed by the appearance of circular pits as exposure continues. At long exposure times, the circular features enlarge and deepen, resulting in a rough surface topography and crack formation. Fourier Transform Infrared Spectroscopy (FTIR) study indicates that the oxidation and chain scission reactions are likely the origins of the surface morphological changes. The relationship between changes in surface roughness and gloss has been analyzed. The root mean square (RMS) roughness of the coating is related to nanoscale and microscale morphological changes in the surface of the coating as well as to the gloss retention. A near-linear dependence of RMS roughness with the measurement length scale (L) is found on a double logarithmic scale, i.e., RMS ~ L f. The scaling factor, f, decreases with exposure time. The relationship between surface topography, on nano- to microscales, and the macroscale optical properties such as gloss retention is discussed. Moreover, a recent development in using an angle-resolved light scattering technique for the measurement of the specular and off-specular reflectance of the UV-exposed specimens is also demonstrated, and the optical scattering data are compared to the gloss and the roughness results. |
DOI : |
10.1007/s11998-008-9108-6 |
En ligne : |
https://link.springer.com/content/pdf/10.1007%2Fs11998-008-9108-6.pdf |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4860 |
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 6, N° 1 (03/2009) . - p. 67-79
[article]
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