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Environmental and time dependence of moisture transportation in an epoxy coating and its significance for accelerated weathering / Shi Xiaodong in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 7, N° 4 (07/2010)
[article]
Titre : Environmental and time dependence of moisture transportation in an epoxy coating and its significance for accelerated weathering Type de document : texte imprimé Auteurs : Shi Xiaodong, Auteur ; Brian R. Hinderliter, Auteur ; Stuart G. Croll, Auteur Année de publication : 2010 Article en page(s) : p. 419-430 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Epoxydes
Revêtements -- Détérioration
Revêtements -- Effets de l'humidité
Revêtements:PeintureTags : 'Revêtement Epoxyde' Détérioration 'Coefficient de diffusion' 'Cycle température' 'Détérioration accélérée' 'Transport eau/humidité' 'Réparation défauts' Index. décimale : 667.9 Revêtements et enduits Résumé : It is increasingly appreciated that water is one of the most important factors in the durability behavior of coatings. The rate of water transportation and the degree of saturation of polymeric coatings depends on exposure history, exposure environment, and the nature of a coating. The focus here is on the time taken for transport of water and the variation it causes in thermal and mechanical properties, which have also been shown previously to have time-dependence that leads to discrepancies between different weathering regimes. This paper studied the effect of moisture on coatings’ mechanical properties and the effect of moisture and temperature on recovery of surface indentation. The reduction of mechanical properties and the increasing rate of surface defect relaxation can be explained in terms of plasticization by water. Recovery of surface defects is related to the appearance and diffusion activity of coatings during exposure. Thermogravimetric analysis showed that the content of moisture in the sample is determined by the ambient humidity, temperature, and the rate of change in these environmental parameters. Diffusion coefficients were determined from the weight change data and an activation energy was obtained via Arrhenius equation. Changes in yellowness, as an example, and signature of chemical degradation, indicated that the cycling period in accelerated weathering may affect the degradation via the amount and distribution of moisture in coatings. Diffusion of moisture is typically slow and limits the possibility of complete drying or saturation in an exposure cycle. Results from the cumulative effect of many cycles will be different depending on the conditions DOI : 10.1007/s11998-009-9209-x En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-009-9209-x.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=9764
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 7, N° 4 (07/2010) . - p. 419-430[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 012362 - Périodique Bibliothèque principale Documentaires Disponible Exterior wood coatings. Part-1 : performance of semitransparent stains on preservative-treated wood in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 8, N° 4 (07/2011)
[article]
Titre : Exterior wood coatings. Part-1 : performance of semitransparent stains on preservative-treated wood Type de document : texte imprimé Année de publication : 2011 Langues : Américain (ame) Catégories : Bois -- Revêtements protecteurs
Bois extérieursTags : 'Taches semi-transparentes' 'Traitement bois' 'Détérioration naturelle' 'Vérification 'Quat cuivre alkalin' (ACQ) 'Azole cuivre' Index. décimale : 667.9 Revêtements et enduits Résumé : Pressure-treated lumber available for residential applications had been changed from chromated copper arsenate (CCA) treatment to Cu-amine formulations (since January 2004). This change created a need to investigate the performance of coatings on these new Cu-based preservatives as compared with CCA. This study evaluated performance of a number of semitransparent deck stains on CCA, alkaline copper quat (ACQ), copper azole (CA), and untreated wood samples during 3 years of natural weathering. Coatings were evaluated for their ability to reduce water uptake, color change, checking of wood, and mildew growth and to improve general appearance of preservative-treated wood samples. Overall, Cu-amine-treated wood had on average 50% higher water uptake than CCA-treated wood samples. Although solvent-based coatings had better water repellency performance on CCA-treated and untreated wood, there was no significant difference in water-repellent effectiveness (WRE) between water-based and solvent-based coatings on ACQ- or CA-treated wood. All preservative-treated woods had less color change and better visual ratings than those of untreated wood samples. Based on image analysis which was used to determine the total area of surface checking on samples after 3 years, preservative treatments had no significant effect on reducing checking of wood while coatings reduced surface checking by 30-40%. DOI : 10.1007/s11998-011-9332-3 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-011-9332-3.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12132
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 8, N° 4 (07/2011)[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 013158 - Périodique Bibliothèque principale Documentaires Disponible Exterior wood coatings. Part-2 : modeling correlation between coating properties and their weathering performance / Mojgan Nejad in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 8, N° 4 (07/2011)
[article]
Titre : Exterior wood coatings. Part-2 : modeling correlation between coating properties and their weathering performance Type de document : texte imprimé Auteurs : Mojgan Nejad, Auteur ; Paul Cooper, Auteur Année de publication : 2011 Article en page(s) : p. 459-467 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Bois -- Revêtements protecteurs
Bois extérieursTags : 'Taches semi-transparentes' 'Traitement pression bois' 'Détérioration naturelle' 'Partial least square-regression (PLS-R) modeling' Index. décimale : 667.9 Revêtements et enduits Résumé : Understanding how a coating’s properties are related to its performance characteristics and how measuring its properties can be used for predicting the performance of coating in service was the main focus of this study. A number of exterior penetrating wood stains were characterized in terms of glass transition temperature (T g), solid content, viscosity, and surface tension. The contact angles of liquid coatings were measured on wood treated with chromated copper arsenate, alkaline copper quat, and copper azole as well as untreated wood. Also, the film thicknesses of the cured coatings on wood surfaces were measured by back-scattered electron imaging of osmium-treated samples. Partial least square-regression (PLS-R) modeling was used to correlate measured coating properties with their weathering performance on the preservative-treated and untreated wood substrates, based on water repellency, color retention, and visual ratings after 3 years of natural weathering. A PLS model was developed with 77% fitting accuracy and 69% prediction ability. This model indicated that preservative treatments significantly affected coating performance, and among coating properties, film thickness, viscosity, and glass transition temperature had the greatest effects on the coatings’ performance in exterior. DOI : 10.1007/s11998-011-9331-4 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-011-9331-4.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=12134
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 8, N° 4 (07/2011) . - p. 459-467[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 013158 - Périodique Bibliothèque principale Documentaires Disponible