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JOURNAL OF COATINGS TECHNOLOGY (JCT) . Vol. 69, N° 872PALS free volume study of dry and water satured epoxies - Technical focus : ResinsMention de date : 09/1997 Paru le : 01/09/1997 |
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Ajouter le résultat dans votre panierInterfacial studies of crosslinked polyurethanes ; Part I. quantitative and structural aspects of crosslinked near film-air and film-substrate interfaces in solvent-borne polyurethanes / Anneke M. Kaminski in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 69, N° 872 (09/1997)
[article]
Titre : Interfacial studies of crosslinked polyurethanes ; Part I. quantitative and structural aspects of crosslinked near film-air and film-substrate interfaces in solvent-borne polyurethanes Type de document : texte imprimé Auteurs : Anneke M. Kaminski, Auteur ; Marek W. Urban, Auteur Année de publication : 1997 Article en page(s) : p. 55-66 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Chimie des surfaces
Cinétique chimique
Evaporation
Hexane
Isocyanates
Polyacrylates
Polymères réticulés
Polyuréthanes
Réticulation (polymérisation)
Revêtements
solvantsIndex. décimale : 667.9 Revêtements et enduits Résumé : One of the reactions leading to the formation of polyurethane (PU) crosslinked networks is the reaction of NCO and OH functionalities. In this study, we examined how crosslinking reactions of hexamethylene diisocyanate isocyanurate and polyacrylate near the film-air (F-A) and film-substrate (F-S) interfaces in urethane coatings may affect crosslink density as well as other network properties. While at the initial stages of the crosslinking reactions, solvent evaporation competes with the urethane network formation and isocyanate consumption changes at various depths from the F-A and F-S interfaces. Quantitative analysis of the NCO consumption as a function of depth showed that the NCO concentrations change from 2.35 x 10-5 to 2.09 x 10-5 M, while going from 0.27 to 1.14 μm. During reaction times not exceeding two to three hours, the NCO consumption at the F-A and F-S interfaces is consumed more rapidly. At low relative humidity conditions, excessive amounts of unreacted NCO exists at both the F-A and F-S interfaces. However, at the extended reaction times, NCO concentration levels at the F-S are greater than at the F-A interface, and the NCO concentration differences can be as high as 3 x 10-5 M. In this study we also examined how crosslinking reactions of hexamethylene diisocyanate (HDI) isocyanurate and polyacrylate near the F-S interfaces in urethane films may affect orientation and distribution of urethane functionalities. Note de contenu : - Sample preparation
- Analytical methods
- Dynamic mechanical thermal analysis measurements (DMTA)
- Solvent specific evaporation rate measurementsPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18281
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Code-barres Cote Support Localisation Section Disponibilité 003541 - Périodique Bibliothèque principale Documentaires Disponible Study of anionic polyurethane ionomer dispersant / Y. S. Huang in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 69, N° 872 (09/1997)
[article]
Titre : Study of anionic polyurethane ionomer dispersant Type de document : texte imprimé Auteurs : Y. S. Huang, Auteur ; S. L. Ding, Auteur ; K. H. Yang, Auteur ; C. P. Chwang, Auteur ; D. Y. Chao, Auteur Année de publication : 1997 Article en page(s) : p. 69-74 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Agents dispersants (chimie)
Dioxyde de titane
IonomèresUn ionomère est un copolymère thermoplastique « réticulé ioniquement ». La réticulation améliore la cohésion du polymère et la conductivité électrique.
Pigments inorganiques
Polyuréthanes
Revêtement émail:Peinture-émail
Revêtements -- Additifs
Revêtements en phase aqueuse:Peinture en phase aqueuse
SurfactantsIndex. décimale : 667.9 Revêtements et enduits Résumé : Anionic polyurethane ionomers designed for use as dispersants in water-soluble acrylic baking enamels were synthesized, and their structures were confirmed by infrared analysis. In an aqueous media, the surface tension of the polyurethane ionomers with different ionic or mixed ionic groups was found to increase with increased concentration of ionic groups, because of the orientation of hydrophobic groups at the air-water interface. It was also found that viscosity in water is higher for a polyurethane ionomer with L-2,5-diaminovaleric acid hydrochloride than for a polyurethane ionomer with dimethylol propionic acid. Polyurethane ionomers with dimethylol propionic acid, p-amino benzoic acid, and mixed dimethylol propionic acid/p-amino benzoic acid were better dispersants for the wettability and dispersion of titanium dioxide (TiO2) in the water-soluble acrylic enamels. The degree of dispersion of TiO2 was found to improve with increased agitation time and anionic polyurethane ionomer concentration. In addition, polyurethanes with dimethylol propionic acid or p-amino benzoic acid or mixtures of these acids improved TiO2 dispersion stability in the baking enamel. Note de contenu : - EXPERIMENTAL : Materials - Method of ionomer preparation - Paint preparation Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18282
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Code-barres Cote Support Localisation Section Disponibilité 003541 - Périodique Bibliothèque principale Documentaires Disponible Influence of crosslink density, glass transition temperature and addition of pigment and wax on the scratch resistance of an epoxy coating / Jacob Lange in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 69, N° 872 (09/1997)
[article]
Titre : Influence of crosslink density, glass transition temperature and addition of pigment and wax on the scratch resistance of an epoxy coating Type de document : texte imprimé Auteurs : Jacob Lange, Auteur ; Alexandre Luisier, Auteur ; Anders Hult, Auteur Année de publication : 1997 Article en page(s) : p. 77-82 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cires
Couches minces
Epoxydes
Pigments
Polymères réticulés
Résistance à l'abrasion
Réticulation (polymérisation)
Revêtements
Revêtements -- Propriétés mécaniques:Peinture -- Propriétés mécaniques
Transition vitreuseIndex. décimale : 667.9 Revêtements et enduits Résumé : The scratch resistance of a series of cationically cured epoxy coatings with varying crosslink densities has been investigated using five different scratch tests. The tests simulate a variety of scratch modes, ranging from single scratches to repeated surface wear. The relative influences of crosslink density and glass transition temperature (Tg) on scratch resistance, as well as the effects of adding pigment and wax to the coatings, were examined. The results show the scratch resistance to increase both with increasing crosslink density and increasing Tg in all tests. It is also shown that adding pigment or wax either increased or decreased the scratch resistance of the coating, depending on which type of scratching was performed. Note de contenu : - Tests on neat coatings
- Influence of pigment and waxPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18283
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Code-barres Cote Support Localisation Section Disponibilité 003541 - Périodique Bibliothèque principale Documentaires Disponible PALS free volume study of dry and water saturated epoxies / M. M. Madani in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 69, N° 872 (09/1997)
[article]
Titre : PALS free volume study of dry and water saturated epoxies Type de document : texte imprimé Auteurs : M. M. Madani, Auteur ; R. R. Miron, Auteur ; R. D. Granata, Auteur Année de publication : 1997 Article en page(s) : p. 45-54 Note générale : Bibliogr. Langues : Américain (ame) Tags : 'Epoxyde résine' 'Polymère réticulé' 'Peinture anticorrosion' Liant 'Volume libre' 'Annihilation positon' Glycol 'Bisphénol A' 'Température transition vitreuse' 'Indice vide' 'Inhibiteur corrosion' 'A sec' 'Saturation eau' 'Etude expérimentale' Index. décimale : 667.9 Revêtements et enduits Résumé : Free volume cavity sizes and fractions of epoxy specimens were determined using positron annihilation lifetime spectroscopy (PALS). PALS data were obtained before and after specimen water equilibration. Specimens were bisphenol A epoxide (B) and/or glycol epoxide (G) cured with a polyamide. Free volume sites increased linearly and cavity sizes decreased linearly with epoxide B:G ratio. Glass transition temperature (Tg) increased with epoxide B:G ratio. Water molecules in wet epoxy B filled approximately six percent of the cavities. Epoxy G cavity size increased 11.4% after water equilibrium and was ascribed to cavity expansion. PALS results differed for commercial corrosion inhibitors in wet and dry mixtures of these epoxides. Note de contenu : - INTRODUCTION : PALS background - Polymer/water interactions
- EXPERIMENTAL : Specimen preparation - PALS
- RESULTS AND DISCUSSION : PALS of 100% epoxy B during cure at room temperature - Direct water uptake and PALS measurements - Free volume cavity concentration (dry) - Free volume cavity concentration (wet) - Free volume and water uptake - Inhibitors and epoxy mixtures - Models of protective coatings systemsPermalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=18298
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Code-barres | Cote | Support | Localisation | Section | Disponibilité |
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003541 | - | Périodique | Bibliothèque principale | Documentaires | Disponible |