Coatings mechanics to defend against the environmental elements / Nicholas Foley in COATINGS TECH, Vol. 17, N° 10 (10/2020)  

[article]  inCOATINGS TECH > Vol. 17, N° 10 (10/2020) . - p. 18-27 Titre : Coatings mechanics to defend against the environmental elements Type de document : texte imprimé Auteurs : Nicholas Foley, Auteur ; Xin Li, Auteur ; Jack Johnson, Auteur Année de publication : 2020 Article en page(s) : p. 18-27 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Applications extérieures Essais d'adhésion Essais dynamiques Résistance à l'allongement Résistance à la fissuration Résistance à la traction Résistance thermique Revêtements -- Détérioration:Peinture -- Détérioration Revêtements -- Effets du climat:Peinture -- Effets du climat Revêtements -- Effets de la température:Peinture -- Effets de la température Revêtements -- Fissuration:Peinture -- Fissuration Statistique Test d'immersion Index. décimale : 667.9 Revêtements et enduits Résumé : Exterior surfaces experience degradative environmental conditions, such as intense UV exposure, rain, and temperature swings, leading to deterioration. Coatings are low-cost solutions offering decades of protection and preventing significant repair costs for buildings. The coating must withstand UV, mitigate water damage, and express the flexibility required to maintain adhesion to dimensionally unstable substrates (i.e., wood) as they undergo thermal expansion and contraction through the days and seasons. we investigated paint film mechanics through accelerated thermal cycling grain crack and tensile testing with intent to correlate the film properties to exterior exposure data. In this article, we demonstrate that adhesion after accelerated weathering, combined with tensile elongation testing, can be used to model outdoor weathering. Note de contenu : - EXPERIMENTAL SETUP : Adhesion testing - Accelerated thermal cycling grain crack test - Exterior exposure - Tensile elongation testing - Tensile elongation testing variables - Statistical data analysis - RESULTS AND DISCUSSION : Exposure series - Freeze/thaw/immersion cycle accelerated testing - Tensile strength and elongation testing at room temperature - tensile strength and elongation testing at low temperature - Tensile strength and elongation testing after accelerated weathering - Adhesion after water conditioning - Developing new methods to predict grain cracking - Table 1 : The full set of 17 paints comprising this study - Table 2 : Comparative thermal cycling conditions - Table 3 : Significant factors for grain cracking in MLR fitting - Fig. 1 : Pine wood section with labels "s" for late wood and "f" for early wood annular rings - Fig. 2 : Comparative width changes for both early and late annular rings. Negative values indicate contraction and positive values indicate expansion - Fig. 3 : Image of cracking rating standard considered in ASTM D611. Originally from the pictorial photographic reference standards contained in the publication Pictorial Standards of Coatings Defects as published by the Federation of Societies for Coatings Technology - Fig. 4 : Grain cracking rating after four years of exposure vs room-temperature strain at break - Fig. 5 : Grain cracking rating after four years of exposure vs 0°C strain at break - Fig. 6 : Grain cracking rating after 4 years exposure vs -20°C strain at break - Fig. 7 : Grain cracking rating after 4 years exposure vs strain at break after seven day QUV - Fig. 8 : Grain cracking rating after four years of exposure vs strain at brak after seven days in the fog box - Fig. 9 : Grain cracking rating after four years of exposure vs adhesion after seven days fog box - Fig. 10 : Coefficients for grain cracking rating in ML model (scaled and centered). A positive coefficient means that as the independent variable increases, the grain crack rating increases. Conversely, a negative coefficient means that the grain crack rating decreases for a given independent variable - Fig. 11 : Observed vs predicted grain cracking rating in MLR model - Fig. 12 : Room temperature strain at breat, after seven days QUV vs fresh sample En ligne : https://drive.google.com/file/d/1k51AsqqgkIemn1paKlRMn5Q-1fYxOAeY/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34725 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
22362	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Optimising pigment distribution / Immanuel Willerich in EUROPEAN COATINGS JOURNAL (ECJ), N° 5 (05/2018)  

[article]  inEUROPEAN COATINGS JOURNAL (ECJ) > N° 5 (05/2018) . - p. 50-55 Titre : Optimising pigment distribution : How interactions of coatings componenfs affect TiO2 efficiency Type de document : texte imprimé Auteurs : Immanuel Willerich, Auteur ; Volodymyr Boyko, Auteur ; Markus Rückel, Auteur ; Jules Mikhael, Auteur ; Nicholas Foley, Auteur Année de publication : 2018 Article en page(s) : p. 50-55 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Agents dispersants (chimie) Chimie analytique Chlorure de polyvinyle Dioxyde de titane Dynamique moléculaire Epaississants Formulation (Génie chimique) Liants Opacité (optique) Pigments Polyacryliques Polyuréthane éthoxylé modifié de façon hydrophobe Revêtements:Peinture Index. décimale : 667.9 Revêtements et enduits Résumé : Understanding the interactions in paints and coatings by ad-vanced analytical methods can help improve properties such as TiO2 usage and hence opacity. It is shown for example why cellulosic thickeners do not create uneven TiO2 distribution but associative thickeners may do so, depending on the choice of dispersant. Note de contenu : - A holistic approach to studying interactions - HEC thickeners show uneven distribution in wet state - But pigment distribution is more even when dry - Problems and solutions in optimising TiO2 usage - Associative thickeners make dispersant choice critical - Effects of associative thickener further confirmed - Binder-pigment interactions can also be observed - Practical value of analytical techniques summarised - FIGURES : 1. Coating constituents in a model paint and their molecular level interactions - 2. Pigment and water distribution as visualised by CLSM ; Top Left : Bright spots are TiO2 particles in wet state visualised by reflectance ; Top Right : Bright spots are water-rich areas stained by a fluorescent water-soluble dye ; Bottom left : dry TiO2 particle distribution ; Bottom right : Model formulation with PVC 20 (HEC: 1 Mio. g/mol, HEUR : low shear) - 3. TiO2 distribution and binder-pigment interaction - 4. Comparison of dispersant-thickener interaction for polyacid and copolymer dispersants in dry straight acrylic model paints containing a HEUR instead of the HEC thickener. Recipe from Fig. 2, acrylic binder - 5. X-ray disc centrifugation of TiO2-binder composites : TiO2 interaction increases in the order A - TABLES : 1. Characterisation of paints with polyacid versus (hydrophobe containing) copolymer dispersants. Spreading rates ah 9 8 % contrast ratio measured according to DIN IS0 13300, rheology measured wiTh Anhon Paar "MCR 302" - 2. Quantitative XDC analysis of pigment composites with binders A, B and C, scattering coefficient and contrast ratio of a commercial PVC 35 paint determined with 7 and 40 mil wet drawdowns En ligne : https://drive.google.com/file/d/1FYloEqq_Glj0DEgPtlmwH56FECCc_aQq/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30589 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
19900	-	Périodique	Bibliothèque principale	Documentaires	Disponible

---

1 (1 - 2 / 2)