Titre : |
Rheological changes during the drying of a waterborne latex coating |
Type de document : |
texte imprimé |
Auteurs : |
Frank Loffläth, Auteur ; Matthew Gebhard, Auteur |
Année de publication : |
1997 |
Article en page(s) : |
p. 55-66 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Evaporation Latex Revêtement -- Séchage:Peinture -- Séchage Revêtements en phase aqueuse:Peinture en phase aqueuse Rhéologie Viscosité
|
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Increases in the low shear viscosity occurring during drying of a water-based latex film were examined as a function of pH, cosolvents, and base. The water and cosolvent evaporation rates were determined as a function of temperature and humidity. Water was found to evaporate with an activity coefficient of 1 and a ΔHv equivalent to pure water. The viscosity changes were determined from a creep measurement. The data is explained by the volume packing model of De Kruif. For several of the films, the ratio between volume and weight fraction was not a static parameter, and an abnormally large drop in the effective volume and weight fraction was observed. This was exaggerated for the samples with ethylene glycol monobutyl ether (EB) or NH4OH. The high volatility of EB explains the former, while the latter result indicates that NH4OH suppresses viscosity during drying. |
Note de contenu : |
- THEORETICAL BACKGROUND : Evaporation process - Viscosity and volume fraction - Combination of evaporation and volume-fraction/ viscosity equations
- EXPERIMENTAL DATA : Raw material and sample preparation - Evaporation measurements - Viscosity increase during evaporation - Intrinsic viscosity - Determination of open time
- RESULT AND ANALYSIS : Evaporation rates - Intrinsic viscosity - Viscosity increase during drying - Physical changes in the sample upon drying - Correlation between drying curve data and open time |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18111 |
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 69, N° 867 (04/1997) . - p. 55-66