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Associative polymer/latex dispersion phase diagrams. II : HASE thickeners / Edward Kostansek in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 2, N° 6 (04/2005)
[article]
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 Latex produced with carboxylic acid comonomer for waterborne coatings : Particle morphology variations with changing pH / Daisuke Fukuhara in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 2, N° 7 (07/2005)
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Titre : Latex produced with carboxylic acid comonomer for waterborne coatings : Particle morphology variations with changing pH Type de document : texte imprimé Auteurs : Daisuke Fukuhara, Auteur ; Donald Sundberg, Auteur Année de publication : 2005 Article en page(s) : p. 509-516 Note générale : Bibliogr. Langues : Américain (ame) Tags : En semi discontinu Particule core shell Modélisation Etude expérimentale Microscopie électronique transmission Méthode étude Cinétique Effet concentration pH Agent surface anionique Méthacrylate de méthyle polymère Relation mise en oeuvre structure Polymérisation ensemencée Acrylate butyle copolymère Styrène Copolymérisation radicalaire Morphologie émulsion Méthacrylique acide Latex Index. décimale : 667.9 Revêtements et enduits Résumé : Carboxylic acid comonomers are often added to latex formulations to improve colloidal stability and to help control the physical structure of composite (core-shell type) particles. We have performed a systematic study of the incorporation of methacrylic acid (MAA) within styrene/butyl acrylate copolymer seed latices, and determined the eventual effect on the morphology of the composite particles when using a second-stage monomer that is either polar (MMA) or nonpolar (BMA). These latices have been produced in batch and semibatch reactions in the pH range of 3-7. At low pH, the MAA groups are not ionized, but at the higher pH they may be nearly completely ionized. Here, we report that for batch reactions carried out within the above pH range, the latex particle morphologies of the PMMA second-stage systems change dramatically with increasing pH, while those for the PBMA system do not change at all. These results show that one cannot easily generalize the effect of acid comonomers on the morphology of composite latex particles, as this depends upon the choice of the copolymers in the latex and the process characteristics of the polymerization reaction. DOI : 10.1007/s11998-005-0010-1 En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-005-0010-1.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3798
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 2, N° 7 (07/2005) . - p. 509-516[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 002327 - Périodique Bibliothèque principale Documentaires Disponible Novel synthesis of carboxy - functional soybean acrylic - alkyd resins for water - reducible coatings / Changchun Wang in JOURNAL OF COATINGS TECHNOLOGY (JCT), Vol. 72, N° 904 (05/2000)
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Titre : Novel synthesis of carboxy - functional soybean acrylic - alkyd resins for water - reducible coatings Type de document : texte imprimé Auteurs : Changchun Wang, Auteur ; Geng Lin, Auteur ; Joon-Hwan Pae, Auteur ; Frank N. Jones, Auteur Année de publication : 2000 Article en page(s) : p. 55-61 Note générale : Bibliogr. Langues : Américain (ame) Tags : Alkyde résine Acrylate copolymère Matériau revêtement Préparation Polycondensation Huile soja Méthacrylique acide Acrylique Polyélectrolyte Relation composition propriété Stabilité chimique Hydrolyse stockage Utilisation Peinture eau Etude expérimentale Index. décimale : 667.9 Revêtements et enduits Résumé : A new process was developed for synthesis of alkyd resins in which a conventional monoglyceride is reacted with a carboxy-functional acrylic ceride is reacted with a carboxy-functional acrylic copolymer. The novel products are called acrylic-alkyd resins. The carboxy-functional acrylic copolymers were synthesized by solution-free radical polymerization. Gelation during alkyd resin synthesis was avoided by; (1) limiting the molecular weight of the acrylic copolymers to Mn 3500-5000 and (2) limiting the number average functionality about 6.5-10 carboxyl groups per molecule. Further, the carboxyl groups were derived from a mixture of acrylic and methacrylic acids (1/1.2 mol ratio) in the expectation that this would help control the process. Three series of acrylic copolymers were prepared from various combinations of acrylic monomers and reacted with a monoglyceride prepared from soybean oil and trimethylol propane. The composition of the acrylic resin was adjusted to minimize phase separation [observed visually and by scanning probe microscopy (SPM)] within cast films. The most satisfactory results were obtained with copolymers of 62-71 wt% of methyl methacrylate, 5-21 wt% of lauryl methacrylate, 7.2 wt% of acrylic acid, and 10.3 wt% of methacrylic acid, In preliminary tests, waterborne coatings made from acrylic-alkyd resins based on these acrylics had excellent stability, with acid numbers changing less than 10% after nine months of storage. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=5807
in JOURNAL OF COATINGS TECHNOLOGY (JCT) > Vol. 72, N° 904 (05/2000) . - p. 55-61[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 001209 - 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)
[article]
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