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Advances in emulsion polymerization for coatings applications / Mohamed S. El-Aasser in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 73, N° 920 (09/2001)
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Titre : Advances in emulsion polymerization for coatings applications : Latex blends and reactive surfactants Type de document : texte imprimé Auteurs : Mohamed S. El-Aasser, Auteur ; E.-D. Sudol, Auteur ; Victoria L. Dimonie, Auteur ; Eric S. Daniels, Auteur ; Xiaoru Wang, Auteur ; Jiansheng Tang, Auteur Année de publication : 2001 Article en page(s) : p. 51-63 Note générale : Bibliogr. Langues : Américain (ame) Tags : Matériau revêtement Peinture eau émulsion Liant Préparation Polymérisation Latex Mélange Adjuvant Agent surface Distribution dimension particule Propriété optique Feuil Brillant Styrène polymère Groupe carboxyle Etude expérimentale Index. décimale : 667.9 Revêtements et enduits Résumé : The utilization of latex blends to prepare zero-VOC coatings and the use of reactive surfactants in emulsion polymerization are two advances in waterborne technology that are of increasing interest to coatings formulators. The first part of this paper focuses on an investigation of the influence of the interface between high and two Tg latex particles on the glass and surface morphologies of films obtained from model latex blends. Glass was influenced by the concentration of carboxyl groups present on the surface of the latex particles (optimal concentration for maximum gloss 3% on the high Tg particles), the degree of neutralization of these groups (higher glass with increased extent of neutralization), the type and concentration of the neutralizing base (higher gloss for stronger bases), and the presence of added surfactant (higher gloss with added surfactant). Gloss was found to be correlated with the surface smoothness of the film. The kinetics, particle size, molecular weight, and location of the reactive surfactant after polymerization, as well as the contact angle of films prepared from these latices, are examined in the second part of this paper. The polymerization rate profiles were similar to those obtained using a conventional surfactant ; however, the dependency of the rate on the number of particles was significantly lower. The amount bound increased and the molecular weight decreased with increasing surfactant concentration. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5746
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 73, N° 920 (09/2001) . - p. 51-63[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 001228 - Périodique Bibliothèque principale Documentaires Disponible Associative polymer/latex dispersion phase diagrams. II : HASE thickeners / Edward Kostansek in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 2, N° 6 (04/2005)
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Titre : Associative polymer/latex dispersion phase diagrams. II : HASE thickeners Type de document : texte imprimé Auteurs : Edward Kostansek, Auteur Année de publication : 2005 Article en page(s) : p. 417-422 Note générale : Bibliogr. Langues : Américain (ame) Tags : Stabilité colloïdale Polymère associatif Propriété thermodynamique Etude expérimentale Peinture Application Effet concentration Dispersion Groupe hydrophobe latéral Méthacrylate de méthyle copolymère aqueuse Acrylate butyle Epaississant Polyélectrolyte d'éthyle Méthacrylique acide Dimension particule Matériau revêtement Floculation Agent surface Diagramme phase Latex Index. décimale : 667.9 Revêtements et enduits Résumé : The colloidal interactions ofHASE associative polymers and latexes in the presence of surfactant are complicated and subject to a number of variables. Both bridging and depletion flocculation can occur, in addition to good particle dispersion. Dispersion phase diagrams have been developed to help visualize these interactions. The various dispersion states can have a significant effect on coating formulations and film properties. Examples of dispersion phase diagrams are presented for a model HASE anionic associative thickener and various model latexes in the presence of sodium dodecylsulfate and nonionic surfactants. The major variables affecting dispersion behavior are associative polymer concentration, latex particle size, latex surface hydrophobicity, electrolyte concentration, and surfactant concentration. The dispersion phase behavior of the HASE systems is compared to that of HEUR thickened systems reported previously. A significant difference is that much less bridging flocculation is observed in the HASE systems. In addition, nonionic surfactants induced depletion flocculation in the HASE systems but not in the HEUR systems. DOI : 10.1007/BF02733884 En ligne : https://link.springer.com/content/pdf/10.1007%2FBF02733884.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3836
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 2, N° 6 (04/2005) . - p. 417-422[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 001483 - Périodique Bibliothèque principale Documentaires Disponible Impact of functional group distribution on the adsorption of a polymeric dispersant / Iwao Soga in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 75, N° 938 (03/2003)
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Titre : Impact of functional group distribution on the adsorption of a polymeric dispersant Type de document : texte imprimé Auteurs : Iwao Soga, Auteur Année de publication : 2003 Article en page(s) : p. 53-58 Note générale : Bibliogr. Langues : Américain (ame) Tags : Polymère Liant Groupe fonctionnel Pigment Adsorption Dispersant Adjuvant Peinture Matériau revêtement Index. décimale : 667.9 Revêtements et enduits Résumé : Binder polymers functionalized with a small amount of polar groups satisfy both the dispersion quality of paints and the mechanical strength of coating films. For industrial-grade polydisperse dispersant polymers, functional groups are not evenly distributed among the polymer chains. The functional group distribution in polyurethane dispersant polymers was investigated by statistical estimation and an adsorption experiment. The polymeric dispersants had a broad functional group distribution and contained a significant amount of non-functionalized chains. By considering the existence of these ineffective chains, the dispersion behavior of the paint was more clearly explained. The described method can be a useful tool to analyze the structure and the properties of polydisperse functionalized polymers for various applications. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5596
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Code-barres Cote Support Localisation Section Disponibilité 000563 - Périodique Bibliothèque principale Documentaires Disponible Polyorthoesters for low-VOC coatings / Hisashi Isaka in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 75, N° 937 (02/2003)
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Titre : Polyorthoesters for low-VOC coatings Type de document : texte imprimé Auteurs : Hisashi Isaka, Auteur ; Yoichi Yonehara, Auteur Année de publication : 2003 Article en page(s) : p. 59-65 Note générale : Bibliogr. Langues : Américain (ame) Tags : Etude expérimentale Feuil Propriété mécanique physique Isocyanate organique Réticulation Durcissement Hydroxyle Groupe fonctionnel Préparation Orthoester Ester polymère Liant Formulation Peinture haute teneur solide Matériau revêtement Index. décimale : 667.9 Revêtements et enduits Résumé : A series of new oligomeric polyorthoesters for low-VOC coatings was prepared by protecting OH groups with orthoester compounds to achieve both low viscosity and excellent compatibility with crosslinking agents. These new oligomeric polyorthoesters were synthesized through a co-condensation reaction among polyol, orthoester, and alpha- or béta-glycol compounds under an acidic condition. Here, the alpha-or béta-glycol compounds were used as stoppers to prevent excessive polymerization. The polyorthoesters can easily be hydrolyzed with atmospheric moisture, and the produced OH groups can react with appropriate crosslinking agents. It is unique in this system that even the stoppers, alpha- or béta-glycol compounds, can react with the crosslinking agents to achieve an extremely low VOC emission. The polyorthoesters cured with polyisocyanate compounds proved to be highly crosslinked polymers showing excellent mechanical properties, chemical resistance, etc. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5607
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Code-barres Cote Support Localisation Section Disponibilité 000562 - Périodique Bibliothèque principale Documentaires Disponible Tailoring HASE rheology through polymer design : Effects of hydrophobe size, acid content, and molecular weight / Wenjun Wu in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 2, N° 6 (04/2005)
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Titre : Tailoring HASE rheology through polymer design : Effects of hydrophobe size, acid content, and molecular weight Type de document : texte imprimé Auteurs : Wenjun Wu, Auteur ; Greg D. Shay, Auteur Année de publication : 2005 Article en page(s) : p. 423-433 Note générale : Bibliogr. Langues : Américain (ame) Tags : Polymère associatif Viscosité cisaillement nul Matériau revêtement Modélisation Propriété rhéologique Etude expérimentale Dispersion aqueuse Peinture Application Solution Relation masse moléculaire propriété Ecoulement cisaillé Modèle composition Latex Epaississant Polyélectrolyte Terpolymère Groupe hydrophobe latéral Méthacrylique acide copolymère Acrylate d'éthyle Index. décimale : 667.9 Revêtements et enduits Résumé : Hydrophobically modified alkali-soluble emulsion (HASE) polymers are an important class of rheology modifiers for waterborne coatings applications. They are typically prepared as terpolymers by emulsion polymerization of ethyl acrylate (EA), methacrylic acid (MAA), and an associative macromonomer. The viscosity development and shear responses of HASE solutions depend on a number of factors. This article presents rheological data reflecting the impacts of three key variables: hydrophobe size, acid content, and molecular weight, on model HASE thickening and rheological performance. The relative contributions of hydrophobic association, chain expansion, and polymer chain length are discussed. In steady shear flow, all thickener solutions approached some constant low-shear viscosity at small deformation rates. At the same molar composition, larger hydrophobe size resulted in higher viscosity development and greater shear thinning behavior. The amount of acid monomer in HASE polymers can influence the balance between hydrophobic attraction and electrostatic repulsion forces. It was found that a minimum of 15 wt% MAA was required to effect dissolution and thickening of the model HASE polymers. Increasing the MAA level yielded higher zero-shear viscosity and storage modulus G' with maximal values being obtained at 40% MAA. The molecular weight of the model thickeners was controlled by the amount of chain transfer agent (CTA) added during polymerization. When the CTA level was below 0.1 wt% based on total monomers, the polymer solutions displayed shear-thinning behavior. A small increase in CTA concentration beyond 0.1% resulted in a dramatic change to Newtonian flow, and the solution viscosity was nearly two orders of magnitude lower. The model thickeners were also tested in a vinyl acrylic architectural paint formulation. The effects of each individual factor on paint thickener efficiency, high-shear, and low-shear properties are discussed and compared with solution rheology for predictive relationships. DOI : 10.1007/BF02733885 En ligne : https://link.springer.com/content/pdf/10.1007%2FBF02733885.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3837
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Code-barres Cote Support Localisation Section Disponibilité 001483 - Périodique Bibliothèque principale Documentaires Disponible