Associative polymer/particle dispersion phase diagrams III : Pigments / Edward Kostansek in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 3, N° 3 (07/2006)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 3, N° 3 (07/2006) . - p. 165-171 Titre : Associative polymer/particle dispersion phase diagrams III : Pigments Type de document : texte imprimé Auteurs : Edward Kostansek, Auteur Année de publication : 2006 Article en page(s) : p. 165-171 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Agents dispersants (chimie) Brillance (optique) Diagrammes de phases Dioxyde de titane Epaississants Floculation Hydrophobie Latex Polyacide méthacrylique Polyacrylate d'éthyle Polyéthers Polyéthylène glycol Revêtements -- Propriétés optiques:Peinture -- Propriétés optiques Revêtements en phase aqueuse -- Additifs:Peinture en phase aqueuse -- Additifs Thermodynamique Index. décimale : 667.9 Revêtements et enduits Résumé : The colloidal interactions of both HEUR and HASE associative polymers with pigments in the presence of dispersant are complicated and subject to a number of variables. The objective of this work was to clarify the conditions needed to achieve good pigment dispersion in associative thickener systems by characterizing particle dispersion behavior. This had previously been done for latex particles, but not for pigments such as TiO2. Good dispersion leads to optical properties, such as gloss and hiding, that are superior to nonassociative thickener systems. Pigment dispersion phase diagrams represent a good way to visualize the complex interactions among pigments, dispersant, and thickener. The two most important variables were found to be pigment type (i.e., surface composition) and dispersant composition. Associative thickeners can yield good pigment dispersion or flocculation, depending on the correct matching of dispersants and pigment type. Because of the hydrophobic functional groups governing associative thickener behavior, dispersants having some hydrophobic character yielded the best pigment dispersions and optical properties because they could couple the pigment particles with the associative thickener network. Interior-grade TiO2 tended to yield better dispersions and optical properties than exterior-grade TiO2. Optimized associative thickener systems generally had improved optical properties over comparable nonassociative systems. Optical properties correlated well with particle dispersion behavior as displayed by the dispersion phase diagrams. DOI : 10.1007/BF02774506 En ligne : https://link.springer.com/content/pdf/10.1007%2FBF02774506.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3689 [article]

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Enhance slower relaxation process of poly(ethyl acrylate) through internal plasticization / X. R. He in INTERNATIONAL POLYMER PROCESSING, Vol. XXIX, N° 3 (07/2014)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXIX, N° 3 (07/2014) . - p. 419-424 Titre : Enhance slower relaxation process of poly(ethyl acrylate) through internal plasticization Type de document : texte imprimé Auteurs : X. R. He, Auteur ; H. Yu, Auteur ; R. Zhang, Auteur ; C.-H. Yang, Auteur Année de publication : 2014 Article en page(s) : p. 419-424 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse mécanique dynamique Caoutchouc Caractérisation Composites à fibres de verre Plastification Polyacrylate d'éthyle Relaxation moléculaire Structure moléculaire Index. décimale : 668.4 Plastiques, vinyles Résumé : In this paper, we report a chemical way to resolve longer motions units in the glass-rubber transition region of poly (ethyl acrylate) (PEA), so called internal plasticization. The ethyl acrylate (EA) monomers were copolymerized with little amount of isoprene (IP) monomers. We propose that the single bonds adjunct to double bonds would have better flexible activity than usual single bonds, so the motion units located between two adjunct double bonds would be enhanced. The dynamic mechanical spectra of internally plasticized PEA (IPPEA) and PEA show that the tan ? of IPPEA is asymmetric, while the tan ? of PEA is symmetric. Furthermore, the results of 2D-DMAS show that the LSM, SRM and RM of IPPEA are located at 7 °C, 12 °C and 36 °C. The shoulder peak of tan ? of IPPEA at higher temperature side was confirmed that it contains sub-rouse mode (SRM) and rouse mode (RM). Thus, internal plasticization is an effective way to resolve modes above Tg. Note de contenu : - Materials - Preparation - Characterization of molecular weight and polydispersity - Characterization of molecular structure - Dynamic mechanical analysis - Two-dimensional analysis DOI : 10.3139/217.2882 En ligne : https://drive.google.com/file/d/1jgIOx1yPD2bjChffIfUDc7vllbL71YRd/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21740 [article]

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Relationship of leather break to grain and flesh layers stress - Strain properties / Jorge A. Vergara in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 63, N° 2 (03-04/1979)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 63, N° 2 (03-04/1979) . - p. 25-27 Titre : Relationship of leather break to grain and flesh layers stress - Strain properties Type de document : texte imprimé Auteurs : Jorge A. Vergara, Auteur ; Alberto Sofia, Auteur ; José Hidalgo van Dick, Auteur ; Victor D. Vera, Auteur Année de publication : 1979 Article en page(s) : p. 25-27 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Emulsions Homopolymères Matériaux -- Imprégnation Polyacrylate d'éthyle Polyacrylate de butyle Polyacrylate de méthyle Polymérisation en émulsion Polyméthacrylate de méthyle Le poly(méthacrylate de méthyle) (souvent abrégé en PMMA, de l'anglais Poly(methyl methacrylate)) est un polymère thermoplastique transparent obtenu par polyaddition dont le monomère est le méthacrylate de méthyle (MMA). Ce polymère est plus connu sous son premier nom commercial de Plexiglas (nom déposé), même si le leader global du PMMA est Altuglas International9 du groupe Arkema, sous le nom commercial Altuglas. Il est également vendu sous les noms commerciaux Lucite, Crystalite, Perspex ou Nudec. Rigidité (mécanique) Rupture (mécanique) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Four impregnating resins (homopolymers) were produced from methyl acrylate, ethyl acrylate, butyl acrylate and methyl methacrylate monomers respectively. The emulsion polymerisation method and other chemical agents were maintained constant. Upper leathers were impregnated with these resins following a statistical design which included non-impregnated leathers as controls. Leather break and stiffness were assessed before and after the impregnating process. The elasticity modulus at 2% extension was measured for ail leathers and also in their respective grain and flesh layers after splitting. From the results obtained several concrete facts emerged. First, the leather break and stiffness increased in the following resins order: butyl acrylate < ethyl acrylate= methyl methacrylate < methyl acrylate. Relationships of the grain layer elasticity modulus to the flesh layer one for the impregnated leathers (Mi grain/Mi flesh) and for the control leathers (Mc grain/Mc flesh) were calculated. It was found that an increase in the difference between these two relationships correlated very well with the increase found in the leather break. On the other hand, when the leathers were impregnated with film forming polymers, their elasticity modulus increased proportionally to the polymer hardness increase. Note de contenu : - EXPERIMENTAL : Impregnating emulsions - Leather ande application of the impregnating resin - RESULTS : Leather break - Stiffness - Elasticity modulus - Table 1 : Emulsion composition - Table 2 : Break (0 = poor ; 10 = escellent) control leather score = 5.0 - Table 3 : Stiffness (0 = soft ; 5 = extremely rigid) (control leather score = 2.0 - Table 4 : Impregnated leather elasticity modulus measured at 2% of strain (g/mm2) (control leather elasticity modulus = 1.444 g/mm2) - Table 5 : Relative variation of elasticity modulus (ΔMR) of grain and corium layers of impregnated leather referred to the control and break increase obtained with each resin emulsion En ligne : https://drive.google.com/file/d/1NNJQVVSKaupq3f55T1L04_U_ORQefQ0e/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34137 [article]

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