Titre : |
Chemical durability of silylated polyurethane-based formulations |
Type de document : |
texte imprimé |
Auteurs : |
Patrice Lehmann, Auteur ; Robert R. Johnston, Auteur |
Année de publication : |
1998 |
Article en page(s) : |
p. 28-32 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Adhésion Formulation (Génie chimique) Immersion Joints d'étanchéité Mastics Polyuréthanes Produits d'étanchéité Résistance chimique Silanes organofonctionnels solvants
|
Index. décimale : |
668.3 Adhésifs et produits semblables |
Résumé : |
Witco Silquest silanes and SPUR technology are designed to allow for tailor-made prepolymers suitable for low to high modulus formulations with identified benefits such as improved UV stability/weatherability and adhesion performance.This study of chemical resistance leads to the conclusion that the inherent benefits of durable siloxane bonding -well-known and anticipated for various coatins applications- extends to silylated polyurethane-(SPU)based sealants. Apparently the synergy of the siloxane crosslinking and the polyurethane chemistry enhances the chemical resistance of these kinds of SPU-based sealants products. The model sealant formulations SPU A and SPU B revealed integrity towards chemical attack when compared to representative commercially available sealants. Immersion in solvents such as diesel fuel, transmission oil and anti-freeze for prolonged periods of time, even at elevated temperature, resulted in minimal changes in mechanical properties when compared to all other representative candidates types of sealants. This result make them particularly suitable for the automotive area such as engine compartment applications.
Whereas all other sealants revealed at last one solvent as particularly problematic, the SPU-based products show the greatest range of chemical resistance over all mechanical properties measured. Generally all these sealants excluding SPU-based products had a significant problem maintaining integrity of modulus.
Sealants based on SPUR technology show the best performance in regard to chemical resistance as a function of temperature.
To further verify these findings other SPU-base laboratory sealants are being added to this evaluation program. This work will extend to adhesion performance tested afeter solvent exposure. The synergy of both improved adhesion performance and good chemical resistance is expected to result in further meaningful benefits. |
Note de contenu : |
- EXPERIMENTAL : Preparation of silylated polyurethane resins - Sealant preparation
- COMMERCIALLY AVAILABLE SEALANT COMPARISONS :
- SAMPLE PREPARATION AND TESTING |
En ligne : |
https://drive.google.com/file/d/1tZSIwEZCvTS1ucYn15auZbClAZKTTKga/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=20135 |
in ADHESIVES AGE > Vol. 41, N° 1 (01/1998) . - p. 28-32