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COATINGS TECH . Vol. 18, N° 2Intertwining of color selection and pigment technology developmentMention de date : 02/2021 Paru le : 11/03/2021 |
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Ajouter le résultat dans votre panierSurface tension studies in colloidal unimolecular polymers / Ashish Zore in COATINGS TECH, Vol. 18, N° 2 (02/2021)
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Titre : Surface tension studies in colloidal unimolecular polymers Type de document : texte imprimé Auteurs : Ashish Zore, Auteur ; Michael van de Mark, Auteur Année de publication : 2021 Article en page(s) : p. 24-31 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Alliages polymères -- propriétés mécaniques
Caractérisation
Granulométrie
Latex
Poids moléculaires
Polycarboxylates
Polymères -- Synthèse
Polymères unimoléculaires colloïdaux
Polysulfones
Polyuréthanes
Tension superficielleIndex. décimale : 668.9 Polymères Résumé : Colloidal unimolecular polymer particles, or CUPs, are true nanoscale charged particles of size less than 10 nm that are made by a simple method that allows for preparation of additive-free, zero-volatile organic content (VOC) and stable dispersions. These CUP particles are made from a single polymer chain containing a well-balanced number of hydrophobic and hydrophilic units (Figure 1). The polymer chain is transformed into a CUP particle because the polymer-polymer interaction exceeds polymer-solvent interaction during the addition of water to the polymer in dilute solution in a low-boiling, water-loving solvent, resulting in collapse of the chain to form a particle.
This process is like formation of micelles, or the water reduction process in water-reducible coatings.1 The charged groups on the surface of the particles provide stability and prevent aggregation due to ionic repulsion. The CUP suspension is free of any additives or surfactants as it contains only charged particles, water, and counterions. Due to the process simplicity, it is easy to control the particle size, charge density on the surface, and composition of these particles.2 CUP particles can also be a good model material for study of protein due to similarities in their size. They can also have potential applications in the field of coatings, drug delivery, catalyst matrix, etc.
CUPs have a great potential in the field of coatings as demonstrated in several publications by Van De Mark et.al. They can be used as coating resin in conjunction with latex and polyurethane dispersions (PUDs) and can be cured with an aziridine3 or a melamine crosslinker4. CUPs with sulfonic acids as the charged stabilizing group can be used as a catalyst for waterborne curing such as acrylic-melamine systems.5 CUPs with amine functional groups CUPs with amine functional groups have been synthesized and used as a crosslinker for waterborne epoxy coatings.6 The CUP particles are hydrated with a layer of water around them, often referred to as surface or bound water, which is non-freezable.Note de contenu : - EXPERIMENTAL : Synthesis of polymer and water reduction - Characterization
- RESULTS AND DISCUSSION : Characterization of polymers - Particle size analysis - Equilibrium surface tension behavior
- Fig. 1 : Formation of CUPs
- Fig. 2 : Surface tension vs concentration behavior for PUD1, PUD2 (solid triangles) and PUD2 diluted to different concentration using 12.9% NMP-water mixture instead of water - Dynamic surface tension behavior
- Fig. 3 : Surface tension vs concentration behavior for polymer 2 (CUPs), PUD1 and latex
- Fig. 4 : Equilibrium surface tension of the carboxylate CUPs (polymers 1 and 2), sulfonate CUPs (polymer), and QUAT-CUPs (polymer 4)
- Fig. 5 : Dynamic surface tension behavior of the latex, PUD1, and CUPs at different surface ages at 3% solids
- Fig. 6 : Dynamic surface tension behavior of the carboxylate (polymer 2), sulfonate (polymer3), and QUAT (polymer 4) CUPs at different surface ages
- Table 1 : Acid number, densities, and molecular weights of the copolymers
- Table 2 : Molecular weights and particle size of the CUPs
- Table 3 : Fitting parameters for dynamic surface tension vs surface age at 0.5 mol/m3 and diffusion coefficient (Dc) at 25°CEn ligne : https://drive.google.com/file/d/1Z_Mny6LNFkOkYOVQS4cTyTGyEAqVV8xm/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35256
in COATINGS TECH > Vol. 18, N° 2 (02/2021) . - p. 24-31[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 22581 - Périodique Bibliothèque principale Documentaires Disponible Silane-modified silicas as functional matting agents / Daniel Clingerman in COATINGS TECH, Vol. 18, N° 2 (02/2021)
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Titre : Silane-modified silicas as functional matting agents Type de document : texte imprimé Auteurs : Daniel Clingerman, Auteur Année de publication : 2021 Article en page(s) : p. 32-36 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Agent mattant
Essais accélérés (technologie)
Formulation (Génie chimique)
Revêtement -- Séchage
Revêtements organiques
Silanes
SiliceLa silice est la forme naturelle du dioxyde de silicium (SiO2) qui entre dans la composition de nombreux minéraux.
La silice existe à l'état libre sous différentes formes cristallines ou amorphes et à l'état combiné dans les silicates, les groupes SiO2 étant alors liés à d'autres atomes (Al : Aluminium, Fe : Fer, Mg : Magnésium, Ca : Calcium, Na : Sodium, K : Potassium...).
Les silicates sont les constituants principaux du manteau et de l'écorce terrestre. La silice libre est également très abondante dans la nature, sous forme de quartz, de calcédoine et de terre de diatomée. La silice représente 60,6 % de la masse de la croûte terrestre continentale.
ViscositéIndex. décimale : 667.9 Revêtements et enduits Résumé : A new silica matting agent has been developed, featuring a mercapto silane-modified surface. Unlike traditional organically modified silicas, which utilize adsorbed waxes on the surface, silane modification offers a new opportunity to introduce reactive functionality into silica additives for coatings. With judicious pairing of surface functionality and resin chemistry, this functionalized surface opens the potential to react with the resin matrix. This paper will highlight this new class of functionalized silica for coatings and outline areas of potential application, with specific emphasis in cobalt (Co)-free alkyd formulations. Note de contenu : - General experimental details
- Results and discussion : 1. Drying time - 2. Viscosity - 3. Gloss reduction - 4. Initial weathering test
- Fig. 1 : Hydrolysis reaction of alkoxy silane under alkaline conditions and condensation of the hydrolyzed alkoxy silane to the silica surface
- Fig. 2 : Drying time comparisons of various silicas with Fe- or Mn-based drier packages. A dry time of 8h refers to the maximum amount of time measured in the experiment and does not account for full cure of the film
- Fig. 3 : Formulation viscosities were measured using a Haake rotational viscometer with a SV1ST spindle. QUL 5120 resins are typically measured at shear rate, D = 40.32 s1, or speed level 5-6
- Fig. 4 : Matting performance of various SAS types in Fe- and Mn-based alkyd systems over the course of 14 days
- Fig. 5 : Gloss retention in Fe-based alkyd systems under QUV-A exposure
- Fig. 6 : Gloss retention in Mn-based alkyd systems under QUV-1A exposure
- Table 1 : Drying starting point formulation from synthopol with iron (Fe)-and manganese (Mn)-based drier packagesEn ligne : https://drive.google.com/file/d/1KYr8pRIWKSh4f_cXXr0UkCTaKoOYKmyM/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35257
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Code-barres Cote Support Localisation Section Disponibilité 22581 - Périodique Bibliothèque principale Documentaires Disponible
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Titre : Additives : More art than science Type de document : texte imprimé Auteurs : Clifford K. Schoff, Auteur Année de publication : 2021 Article en page(s) : p. 40 Langues : Américain (ame) Catégories : Revêtements -- Additifs
Revêtements organiquesIndex. décimale : 667.9 Revêtements et enduits Résumé : Additives modify paint or film properties or behavior, preferably (but not always) improving them. They are critical to successful formulation and to solving all kinds of paint problems, but choosing the right one can be exceedingly difficult and usually involves extensive trial and error.
Many different types of additives are available and there are many different products within a given type. Detailed coverage would take many pages, rather than just one, but here are comments regarding a variety of additive types.Note de contenu : - Surfactants
- Rheology modifiers
- Defoamers/antifoams
- Adhesion improvers
- Slip aids
- Solvents as additives
- Coalescing solvents
- Resins as additives
- RecommendationsEn ligne : https://drive.google.com/file/d/1YwmJOylHNzfFE_9aoqHE7GxJHF56av28/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35258
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