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Ajouter le résultat dans votre panier Affiner la rechercheCharacterization of mar/scratch resistance of polymer coatings : Part 1 / Weidian C. Shen in COATINGS TECH, Vol. 3, N° 3 (03/2006)
Titre : Characterization of mar/scratch resistance of polymer coatings : Part 1 Type de document : texte imprimé Auteurs : Weidian C. Shen, Auteur Année de publication : 2006 Article en page(s) : p. 54-60 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 667.9 Revêtements et enduits Résumé : This two-part article briefly reviews the development of mar/scratch characterization techniques, and focuses on single-probe tests with nano instruments which have been widely used recently. Quantitative measurements of micro mar resistance (MMR), different responses of the coatings to the marring stress (i.e., elastic response, plastic deformation, and abrasive wear), and critical forces for rough trough, cracking, delamination, and chipping are described, as are some complementary test methods. Statistical investigation of damage on samples used in real environments, combined with laboratory mar/scratch tests on these samples, could determine the force distribution curve in the lab which is approximately equivalent to the field conditions. The curve is useful for development of new coatings, and it can predict the weights of different damage modes that are likely to occur at the surface of the coatings in the field. The weights, combined with the quantification of the damage levels of different modes, allow calculation of a quantitative index to characterize the mar/scratch resistance of a coating in a specific environment comprehensively. To better understand the mar/scratch resistance behavior of tested materials, a detailed stress-strain study is needed, utilizing theoretical analysis and finite element modeling to complement the experimental measurements described here as an integrated approach. En ligne : https://drive.google.com/file/d/1VWfFzgsN3iXO8uQQUS5Vc1B-PfHcb3sn/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5490
in COATINGS TECH > Vol. 3, N° 3 (03/2006) . - p. 54-60[article]Réservation
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Titre : Characterization of mar/scratch resistance of polymeric coatings : Part II Type de document : texte imprimé Auteurs : Weidian C. Shen, Auteur Année de publication : 2006 Article en page(s) : p. 44-51 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 667.9 Revêtements et enduits Résumé : This two-part article (Part I was published on pages 54-60 in the March 2006 issue of JCT CoatingsTech) briefly reviews the development of mar/scratch characterization techniques, and focuses on single-probe tests with nano instruments which have been widely used recently. Quantitative measurements of micro mar resistance (MMR), different responses of the coatings to the marring stress (i.e., elastic response, plastic deformation, and abrasive wear), and critical forces for rough trough, cracking, delamination, and chipping are described, as are some complementary test methods. Statistical investigation of damage on samples used in real environments, combined with laboratory mar/scratch tests on these samples, could determine the force distribution curve in the lab which is approximately equivalent to the field conditions. The curve is useful for development of new coatings, and it can predict the weights of different damage modes that are likely to occur at the surface of the coatings in the field. The weights, combined with the quantification of the damage levels of different modes, allow calculation of a quantitative index to characterize the mar/scratch resistance of a coating in a specific environment comprehensively. To better understand the mar/scratch resistance behavior of tested materials, a detailed stress-strain study is needed, utilizing theoretical analysis and finite element modeling to complement the experimental measurements described here as an integrated approach. En ligne : https://drive.google.com/file/d/1Srm2p0oI5RWIbxnsmqsd7Pd_VQuNX9pd/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5487
in COATINGS TECH > Vol. 3, N° 4 (04/2006) . - p. 44-51[article]Réservation
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Titre : Investigation of the effect of precoalescence or postcoalescence crosslinking on film formation, properties, and latex morphology Type de document : texte imprimé Auteurs : Ravi G. Joshi, Auteur ; Frank N. Jones, Auteur ; Weidian C. Shen, Auteur ; Wenjing Mao, Auteur ; Paul D. Ziemer, Auteur ; Theodore Provder, Auteur Année de publication : 2009 Note générale : Erratum in Journal of coating technology and research Vol. 7, N° 4, p. 529-530 - Bibliogr. Langues : Américain (ame) Catégories : Coalescence (Sciences physiques)
Contraintes (mécanique)
Formation de film
Indentation des matériaux
Latex
Morphologie (matériaux)
Réticulation (polymérisation)
Revêtements:PeintureIndex. décimale : 667.9 Revêtements et enduits Résumé : Latexes have many product applications including functioning as a binder in coatings. For many years, coatings researchers in industry as well as in academe have been exploring various modes of crosslinking latexes. Quite often, the goal of preparing crosslinked latexes is to upgrade film properties relative to the film properties of uncrosslinked latexes. In the present report, the synthesis and properties of crosslinkable acrylic latexes prepared with either an internal crosslinker (1,3-butylene glycol dimethacrylate)—"precoalescence crosslinking"—or an external crosslinker (adipic dihydrazide)—"postcoalescence crosslinking"—at various levels of crosslinking were studied. For postcoalescence crosslinking, diacetone acrylamide was copolymerized into the latex to provide sites for subsequent reaction with adipic dihydrazide. Fundamental properties of films cast from the two types of latexes were systematically compared. These properties included gel content, dynamic mechanical properties, nano-indenter hardness and modulus, stress–strain properties as well as the characterization of latex morphology by atomic force microscopy (AFM). In addition, some specific end-use properties were determined. This study assesses the effect of type (precoalescence or postcoalescence) and level of crosslinking on the film formation process and the resulting fundamental and end-use properties as well as resulting latex film morphology. DOI : 10.1007/s11998-008-9115-7 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-008-9115-7.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4859
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 6, N° 1 (03/2009)[article]Réservation
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Titre : Measurement of mar resistance and study of marring mechanism of polymeric coatings with scanning probe microscope Type de document : texte imprimé Auteurs : Weidian C. Shen, Auteur ; Frank N. Jones, Auteur ; Bin Jiang, Auteur Année de publication : 2000 Article en page(s) : p. 89-95 Note générale : Bibliogr. Langues : Américain (ame) Tags : Matériau revêtement Peinture Feuil Dégradation Propriété mécanique Résistance abrasion Etude expérimentale Microscopie champ proche Index. décimale : 667.9 Revêtements et enduits Résumé : A scanning probe microscope (SPM) equipped with a custom-made probe, consisting of a diamond tip and rectangular tungsten cantilever, was used to measure the mar resistance of crosslinked polymeric surface coatings at micron and submicron scales. The term mar is used to describe the surface damage of coatings, which may not be readily noticeable individually, however, the existence of many mars does degrade the appearance of coatings. Good mar resistance is a requirement for many coatings applications. With the unique high resolution of the SPM, the dimension of the mars can be measured with great accuracy, thus different responses of coatings to the marring stress, i.e., elastic recovery, plastic deformation, and abrasive wear, can be identified quantitatively. In addition, the dynamic process of marring, including viscoelastic creep, strain-hardening, micro-cracking, and surface fatigue, has also been studied with the SPM. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5856
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 72, N° 907 (08/2000) . - p. 89-95[article]Réservation
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Titre : Methods for studying the mechanical and tribological properties of hard and soft coatings with a nano-indenter Type de document : texte imprimé Auteurs : Weidian C. Shen, Auteur ; Frank N. Jones, Auteur ; Paul D. Ziemer, Auteur ; J. David Nordstrom, Auteur ; Wenjing Mao, Auteur ; Zhiqiang Liu, Auteur ; Jian Sun, Auteur Année de publication : 2004 Article en page(s) : p. 117-125 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Dureté (matériaux)
Indentation des matériaux
Latex
Polyacryliques
Résistance à l'abrasion
Revêtements -- Propriétés mécaniques:Peinture -- Propriétés mécaniques
ThermoplastiquesUne matière thermoplastique désigne une matière qui se ramollit (parfois on observe une fusion franche) d'une façon répétée lorsqu'elle est chauffée au-dessus d'une certaine température, mais qui, au-dessous, redevient dure. Une telle matière conservera donc toujours de manière réversible sa thermoplasticité initiale. Cette qualité rend le matériau thermoplastique potentiellement recyclable (après broyage). Cela implique que la matière ramollie ne soit pas thermiquement dégradée et que les contraintes mécaniques de cisaillement introduites par un procédé de mise en forme ne modifient pas la structure moléculaire.Index. décimale : 667.9 Revêtements et enduits Résumé : This study illustrates the capabilities of a nanoindentation/nanoscratch tester to assess mechanical and tribological properties of coating films. Properties such as hardness, elastic modulus, mar and scratch resistance, and critical force for cracking can be accurately measured. Operation of the Nano-Indenter is described in detail. A scanning probe microscope (SPM) is shown to be a valuable supplement to the Nano-Indenter. Well-characterized thermoset acrylic clearcoats and thermoplastic latex films were studied. For the first time, operating parameters are described for measurement of relatively soft coatings, such as films cast from a latex with a glass transition temperature (Tg) of 8°C. Thus, the method is made available for study of most types of coatings. The method can easily discriminate between coatings with different Tgs and crosslink densities. Once operating parameters are established, it takes about 10 minutes for an indentation test and 10 minutes for a scratch test with the Nano-Indenter, and with further automation this time could be reduced. Each indtntation test accurately measures hardness and elastic modulus as a function of depth within the coating, and each scratch test provides additional insight into the material's behavior. The method is sensitive to small changes in polymer composition and formulation, and results are highly reproducible. DOI : 10.1007/s11998-004-0006-2 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-004-0006-2.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3957
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 1, N° 2 (04/2004) . - p. 117-125[article]Réservation
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