Titre : |
Application of polycarbonate diol containing hindered urea to polyurethane-based clearcoats for tuning of scratch-healing properties |
Type de document : |
texte imprimé |
Auteurs : |
Dong Geun Lee, Auteur ; Sujin Sung, Auteur ; Dae Geun Oh, Auteur ; Young Il Park, Auteur ; Sang-Ho Lee, Auteur ; Jin Chul Kim, Auteur ; Seung Man Noh, Auteur ; Hyun Wook Jung, Auteur |
Année de publication : |
2020 |
Article en page(s) : |
p. 963-976 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Catégories : |
Analyse mécanique dynamique Nanotechnologie Polycarbonates Polymères autoréparants Polyuréthanes Rayures Revêtement autoréparant:Peinture autoréparante Rhéologie Vernis
|
Index. décimale : |
667.9 Revêtements et enduits |
Résumé : |
Newly synthesized polycarbonate diols containing hindered urea (PCD-HUs) were employed to modify the scratch-healing properties of conventional two-component clearcoats. To elucidate their contributions to the crosslinking properties of the coatings under conventional thermal curing (150°C), the real-time rheological properties of the clearcoat mixtures were measured using a rotational rheometer in the small-amplitude oscillatory shear mode. A dynamic mechanical analysis was carried out to compare the thermomechanical properties of the cured clearcoat free films. PCD-HU, a key component for the tuning of the scratch-healing, was further identified by analyzing the clearcoat layer cured over a phosphated metal substrate with undercoats such as primer and basecoat as a precoated metal (PCM) sheet. Elastic recovery and scratch profiles of the outermost clearcoat layer in the PCM sheet were acquired through nano-indentation and nano-scratch tests by gradually increasing the quantitative normal force. Finally, the healing patterns of the scratches on various clearcoat layers at a certain normal force were visualized by three-dimensional and one-dimensional cross-cut images using atomic force microscopy under specified temperature and healing time conditions. The surface durability provided by the PCD-HU in the clearcoat layer was confirmed by repeated scratching and healing tests on the same surface positions. Therefore, the coating layer containing HU, which possessed similar surface mechanical properties to those of conventional references, exhibited better scratch-healing performance. |
Note de contenu : |
- EXPERIMENTAL METHODS : Preparation of PCD-HUs - Preparation of clearcoat coatings and their property measurements - Elastic recovery and scratch-healing properties of the clearcoat layers
- RESULTS AND DISCUSSION : Real-time rheological properties of the clearcoats during the thermal curing - Thermomechanical properties of the clearcoat free films - Indentation and related elastic recovery properties of the cured clearcoat layers in the PCMs - Scratch properties of the cured clearcoat layers in the PCMs - Scratch-healing pattern analysis by AFM - Durability features through repeated scratching and healing procedures |
DOI : |
https://doi.org/10.1007/s11998-019-00316-0 |
En ligne : |
https://link.springer.com/content/pdf/10.1007/s11998-019-00316-0.pdf |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34384 |
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 17, N° 4 (07/2020) . - p. 963-976