Titre : |
Characterization and rheological investigation of polymer microgels used in automotive coatings |
Type de document : |
texte imprimé |
Auteurs : |
Lori J. Boggs, Auteur ; M. Rivers, Auteur ; S. G. Bike, Auteur |
Année de publication : |
1996 |
Article en page(s) : |
p. 63-73 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Automobiles -- Revêtements:Automobiles -- Peinture Caractérisation Colloides Haut extrait sec Polymères Revêtements -- Additifs Rhéologie Viscosité
|
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
The mechanism by which polymer microgels impart shear-thinning behavior and a yield stress to the Newtonian, low molecular weight resin of high-solids solvent-borne automotive coatings is not well understood. Toward identifying this mechanism, we measured the viscosity of several microgel dispersions as a function of particle volume fraction as well as the size and polydispersity of the particles. Variations in the relative softness of the particles, due to differences in the steric layer thickness or crosslink density of the particles, gave rise to differences in the viscometry behavior. When dispersed in acrylic polymer solutions, the microgels induced a yield stress that displayed a power-law dependence on particle concentration. Dynamic oscillatory measurements were used to investigate the nature of the structure formed by the microgels. The mechanim of structure formation can be attributed to depletion flocculation when the polymer does not absorb to the microgels and to bridging flocculation when the polymer does absorb. |
Note de contenu : |
- EXPERIMENTAL : Materials - Scanning electron microscopy - viscometry
- RESULTS AND DISCUSSION : Microgels - Yiel value measurements - Structure formation measurements - |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18324 |
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 68, N° 855 (04/1996) . - p. 63-73