| Titre : |
Preparation of an ionic/nonionic polyurethane-silicone dispersion (PUSD) with a high solid content and low viscosity using complex soft segments |
| Type de document : |
texte imprimé |
| Auteurs : |
Xiaoli Wei, Auteur ; Faxing Zhang, Auteur |
| Année de publication : |
2018 |
| Article en page(s) : |
p. 1229-1237 |
| Note générale : |
Bibliogr. |
| Langues : |
Américain (ame) |
| Catégories : |
Copolymère silicone-uréthane
Dispersions et suspensions
Dispersions et suspensions -- Stabilité
Haut extrait sec
Hydrophobie
Particules -- Morphologie
Résistance aux conditions climatiques
Revêtements en phase aqueuse
Rhéologie
Taille des particules
|
| Index. décimale : |
667.9 Revêtements et enduits |
| Résumé : |
A series of ionic/nonionic polyurethane-silicone dispersions (PUSDs) with a high solid content and low viscosity were prepared using isophorone diisocyanate as the hard segment, polytetrahydrofuran polyether diol (PTMG) and polysiloxane diol (PESI) as the complex soft segments and an ionic/nonionic low molecular weight polyether diol (DPSA) as the hydrophilic, chain-extending agent. The morphologies and rheological properties of the ionic/nonionic PUSD were examined using particle-size, TEM, and viscosity analyses. The hydrophobic and mechanical properties of the dispersions were also tested. It was found that under the conditions of a constant NCO/OH ratio (2/1) and weight percentage of DPDA (6%), the PUSD dispersions with higher PESI contents possessed higher average particle diameters and wider particle-size distributions. Particles in the PUSD dispersions are generally spherical and have a typical core–shell structure due to the use of complex soft segments. However, the solid content of the ionic/nonionic PUSD increased first and then decreased as the weight ratio of PESI to PTMG increased. When the ratio ranged from 4/10 to 6/10, the max solid content of the ionic/nonionic PUSD reached up to 58%, but the viscosity of the PUSD was less than 400 mPa.s−1. Meanwhile, the water contact angle of the films increased due to the formation of a crosslinking structure on the side of the PUSD macromolecule, and when the weight ratio of PESI to PTMG varied from 3/10 to 7/10, the water contact angle of the films increased from 48.3° to 72.3°. In addition, both the freeze-thaw and thermal stabilities of the PUSD dispersions were enhanced as the weight ratio of PESI to PTMG increased. The PUSD coating had good mechanical properties as well. |
| Note de contenu : |
- EXPERIMENTAL : Materials - Synthesis of the polyurethane-silicone dispersions (PUSDs) - Characterization
- RESULTS AND DISCUSSION : Average particle diameter and distribution of the dispersions - Particle morphology of the dispersions - Rheology of the dispersions - The stability of the dispersions - The hydrophobic properties of the PUSD films - The mechanical properties of the PUSD coating |
| DOI : |
10.1007/s11998-018-0063-6 |
| En ligne : |
https://link.springer.com/content/pdf/10.1007%2Fs11998-018-0063-6.pdf |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31333 |
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 15, N° 6 (11/2018) . - p. 1229-1237
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Preparation of an ionic/nonionic polyurethane-silicone dispersion (PUSD) with a high solid content and low viscosity using complex soft segments in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 15, N° 6 (11/2018)
