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Approaches to minimize titanium dioxide consumption in coatings- a review / Nandkumar Kadam in PAINTINDIA, Vol. LXIX, N° 9 (09/2019)
Titre : Approaches to minimize titanium dioxide consumption in coatings- a review Type de document : texte imprimé Auteurs : Nandkumar Kadam, Auteur ; Pratiksha Chaher, Auteur ; Nilesh Mhatre, Auteur ; Mahesh Kadam, Auteur Année de publication : 2019 Article en page(s) : p. 77-84 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Argile
Bilan des émissions de gaz à effets de serre
CalcinationLa calcination est une technique de préparation d'échantillon utilisée en chimie analytique qui permet de prendre en compte ce phénomène. Elle consiste à chauffer l'échantillon à haute température (typiquement 500 à 1 000 °C) sous air ou sous atmosphère neutre pour provoquer des réactions physiques et chimiques et mettre ainsi l'échantillon dans un état de référence.
En effet, un certain nombre de propriétés des matériaux dépendent de la température et de l'historique de l'échantillon comme de l'humidité. La calcination permet de l'abstraire de ces effets et donc d'avoir des mesures reproductibles, de pouvoir comparer différents échantillons. En revanche, il faut être conscient que l'échantillon analysé n'est pas l'échantillon prélevé. La méthode est similaire à l'analyse des extraits secs mais utilise une température plus élevée.
Dioxyde de titane
Dioxyde de titane -- Suppression ou remplacement
Sphères creusesIndex. décimale : 667.9 Revêtements et enduits Résumé : Titanium dioxide (TiO2) is closely associated with paint industry as a white pigment. Its efficient light scattering phenomenon delivers high brightness and good opacity. The increasing market demand, cost, limited resources and an energy intensive manufacturing process demands for the either complete or partial substitution of TiO2. This review article discusses briefly about the changing trends of TiO, substitution in paint industries. Many substitutes viz ; kaolin, clay, calcium carbonate (both untreated and calcined) and hallow latex spheres, along with other alternatives are reviewed. Note de contenu : - FACTORS GOVERNING THE SUBSTITUTIONS MARKET : Lifetime quality - Possible reactions - Price - Resource availability
- CHEMISTRY OF TiO2
- ALTERNATIVE OF TiO2 : Direct replacements (Zinc oxide - Impregnated TiO2) - Top-down approaches (Calcium carbonate (CaCO2) - Clay minerals - Kaolin - Talc - Perlite - Calcined clays) - Bottom-up approaches (Hollow latex spheres - Hollow glass spheres) - Precipitation (Precipitation method - Spray precipitation) - Nanorattles - Spacers of TiO2 - Others way to reduce TiO2 consumption
- Fig. 1 : Rutile and antase TiO2
- Fig. 2 : Opacity of materials
- Fig. 3 : Spheres produced from 24 Li2O-12Al2O3-64B2O3 glass. Nearly all particles have been spherodized by the torch method, regardless of size
- Fig. 4 : Scanning electron micrographs showing the morphology of nano and micro scale aluminum chlorhydrate (ACH) particles
- Fig. 5 : Nanorattles containing TiO2
- Table 1 : Mine production and estimated titanium ore production in thousands of tons
- Table 2 : Refractive index, refractive tinting strength and specific gravity of some white pigments
- Table 3 : Analysis of alternatives to TiO2. Average values for each alternative's properties and the number of responses between bracketsEn ligne : https://drive.google.com/file/d/1sGHY8lzNYxWvaRz_Bty689pvPR4gcMuY/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33074
in PAINTINDIA > Vol. LXIX, N° 9 (09/2019) . - p. 77-84[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 21228 - Périodique Bibliothèque principale Documentaires Disponible
Titre : Evaluation of glass bubbles for solar heat reflection in waterborne acrylic elastomeric roof coatings Type de document : texte imprimé Auteurs : Kevin Rink, Auteur ; Andrea Charif Rodriguez, Auteur Année de publication : 2016 Article en page(s) : p. 40-48 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Charges (matériaux)
Chlorure de polyvinyle
Economies d'énergie
Elastomères
Essais accélérés (technologie)
Formulation (Génie chimique)
Polyacryliques
Réflectivité thermique
Revêtements:Peinture
Sphères creuses
VerreIndex. décimale : 667.9 Revêtements et enduits Résumé : In this study, all of the white paints generally exhibit industry acceptable initial solar reflectance index values,2 and thus offer varying degrees of potential savings over a black roof baseline. Paints made with glass bubbles offered the highest degree of potential energy savings based on the fillers studied in this experiment. This study does not take into account the other parameters that qualify an acceptable elastomeric roof coating such as elongation, water resistance, etc. Final formulations need to be tested for ail specified properties to determine final acceptante per customer specifications. New studies have suggested maintaining certain minimum SRI values after actual outdoor weathering intervals. These and other studies such as the impact of glass bubbles on the solar reflectance of colored paints may form the basis for future studies. The white elastomeric paints in this study target low sloped roofs such as those utilized in industrial applications. Higher sloped roofs using other colors for residential applications could potentially benefit from these same materials.
White elastomeric waterborne acrylic roof coatings made with glass bubbles can offer formulators an alternative to other conventional fillers used in these coatings. The smaller glass bubbles offer increased solar reflectance and thermal advantages, which in turn could result in energy savings. The smaller bubbles also offer higher strength which could be beneficial for higher pressure applications such as airless spraying. In addition, the smaller bubbles yield a smoother appearance and good dirt pick-up resistance. The magnitude of these benefits needs to be evaluated by each formulator for their particular application and formulation.Note de contenu : - Opacity, gloss, and thickness
- Solar reflectance
- Thermal emittance test
- Infrared heat lamp test
- GB3 loading (PVC) study
- Accelerated weathering studies
- Additional experiment : using glass bubbles as a post-addition additive
- Energy savingsEn ligne : https://drive.google.com/file/d/1wrJfZjtAQkhR7SxdqkAdAKT6xNW9AyET/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27048
in COATINGS TECH > Vol. 13, N° 9 (09/2016) . - p. 40-48[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18377 - Périodique Bibliothèque principale Documentaires Disponible
Titre : Excellent resistance at reduced weight : The qualification of suitable foam injection molding processes enables the use of thermosets in lightweight construction applications Type de document : texte imprimé Auteurs : Christian Hopmann, Auteur ; Maximilian kramer, Auteur ; Stefan Haase, Auteur Année de publication : 2019 Article en page(s) : p. 28-31 Langues : Anglais (eng) Catégories : Agents d'expansion (chimie)
Matériaux -- Allègement
Matières plastiques -- Moulage par injection
Matières plastiques -- Propriétés mécaniques
Sphères creusesIndex. décimale : 668.4 Plastiques, vinyles Résumé : The transfer of foam injection molding from thermoplastic to thermoset processing has not yet been implemented in industrial practice. IKV Aachen has investigated this transfer and has precisely analyzed the economic efficiency of the process and the potential for lightweight construction. Note de contenu : - Which foaming processes are suitable ?
- Hollow glass spheres as an alternative
- Studies with chemical blowing agents
- Pros and cons of hollow glass spheres
- Cost comparison facilitates process selection
- Figure : Foamed thermosets can be used to produce low-density thermally resistant components at low cost
- Fig. 1 : The expansion of the chemical blowing agent in thermoset foam injection molding is similar to thermoplastic foam injection molding in the mold, but the reaction is thermally initiated
- Fig. 2 : The specimen geometry allows the analysis of different material properties
- Fig. 3 : Influence of the process parameters : with an increasing blowing agent content the component weight is reduced. The results of the mechanical analysis are shown on the right
- Fig. 4 : In addition to an increasing content of hollow glass spheres (HGS,) decreasing melt temperatures and injection speeds leat to lower component weights. The stiffness and impact strength can even be improved
- Fig. 5 : The cost comparison calculation shows that the use of chemical blowing agent results in an economic advantage for large quantities. Hollow glass spheres, on the other hand, improve the mechanical propertiesEn ligne : https://drive.google.com/file/d/1i85hS5I34K35GwyaKLUowwPd8M4Mf9o0/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33654
in KUNSTSTOFFE INTERNATIONAL > Vol. 109, N° 11 (11/2019) . - p. 28-31[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 21285 - Périodique Bibliothèque principale Documentaires Disponible
Titre : Flashing method for fabricating micro scale fibers, spheres, porous and condensed polymer structures Type de document : texte imprimé Auteurs : R. Porwal, Auteur ; J. R. Bellare, Auteur Année de publication : 2017 Article en page(s) : p. 34-40 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Diagrammes de phases
Matériaux poreux
Matières plastiques -- Extrusion:Polymères -- Extrusion
Microfibres
Polyéthylène téréphtalate
Solutions de polymère
Sphères creusesIndex. décimale : 668.4 Plastiques, vinyles Résumé : Micro and nano structures have unique properties such as large specific surface area, high porosity and smaller diameter size. They have several potential applications in textile industries, filtration systems and biomedicine. Common methods employed for fabrication of nanofibers include electrospinning, force spinning, biocomponent spinning and melt blowing. Flashing provides an easy method to produce discrete fibers from higher molecular weight polymers. Its production rate is also high compared to conventional methods, making it an attractive technique. Experiments were performed using the flashing method in which a polymer is dissolved in a suitable solvent at supercritical conditions of temperature and pressure. Then, the formed homogeneous solution was extruded through a nozzle at high speed into a zone of substantially lower temperature and pressure. Polyethylene terephthalate was used as the polymer while dichloromethane and Freon 12 were the solvents. By changing various parameters in the experiment, a variety of structures such as micro scale fibers, spheres, porous structures as well as condensed irregular structures were obtained. Further, ESEM, cryo FEG SEM and porosity measurements were carried out on the samples obtained to study their external and internal structures. We have identified morphological phase space of this system so that the microstructure can be tuned to the desired state based on process parameters. Note de contenu : - EXPERIMENTAL : Materials - Flashing process - Characterization
- RESULTTS AND DISCUSSION : Types and dimensional range of structures obtained - effects of process parameters on microstructures - Phase diagram for variation in structuresDOI : 10.3139/217.3228 En ligne : https://drive.google.com/file/d/1Jxkcq-VsnysXH3UXsfqiHN4dH9TpvPIj/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27977
in INTERNATIONAL POLYMER PROCESSING > Vol. XXXII, N° 1 (03/2017) . - p. 34-40[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18732 - Périodique Bibliothèque principale Documentaires Disponible
Titre : Hollow thermoplastic microspheres in elastomeric cool roof coatings Type de document : texte imprimé Auteurs : Jan Nordin, Auteur ; Olof Sandin, Auteur ; Peter Greenwood, Auteur Année de publication : 2019 Article en page(s) : p. 20-27 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Elastomères
Isolation thermique
Microsphères
Réflectance
Réflectivité thermique
Sphères creuses
ThermoplastiquesUne matière thermoplastique désigne une matière qui se ramollit (parfois on observe une fusion franche) d'une façon répétée lorsqu'elle est chauffée au-dessus d'une certaine température, mais qui, au-dessous, redevient dure. Une telle matière conservera donc toujours de manière réversible sa thermoplasticité initiale. Cette qualité rend le matériau thermoplastique potentiellement recyclable (après broyage). Cela implique que la matière ramollie ne soit pas thermiquement dégradée et que les contraintes mécaniques de cisaillement introduites par un procédé de mise en forme ne modifient pas la structure moléculaire.
Toiture -- RevêtementsIndex. décimale : 667.9 Revêtements et enduits Résumé : Hollow ultra-low density thermoplastic microspheres can be used as filler in elastic waterproof/cool roof coatings to improve a number of important properties of the coatings. Micron-sized hollow microspheres have a surprisingly strong effect on reflecting solar radiation and reducing the temperature of cool roof coatings. Results from solar reflectance measurements show that the coating system filled with hollow microspheres reflects solar radiation of all incoming wavelengths. Hollow microspheres can be combined with reflecting pigments, making it possible to formulate coatings with extremely high values for total solar reflectance (TSR).
Dirt pick-up resistance (DPUR) is not significantly affected by the choice of filler for the formulations evaluated here. This article presents convincing results that DPUR can be drastically improved by adding surface modified silica nanoparticles to the formulations. The silica nanoparticles tend to migrate to the coating surface and affect both the surface energy and the tackiness of the surface.
Adhesion to steel surfaces is significantly improved by exchanging the inorganic filler for thermoplastic hollow microspheres. This effect is true for both wet and dried coatings and will help improve the water-proofing properties of the coating. It is likely that the thermoplastic properties of the hollow fillers count for part of this effect.Note de contenu : - Fig. 1 : Solar energy distribution. About 5% of the incoming energy is found in the UV-region, 43% in the visible region, and some 52% is found in the near-IR region
- Fig. 2 : Spectral reflectance measurements on aged coatings (dry thickness O.8 ± 0.05 mm) filled with 37 vol % CaCO3, 18.5 vol % CaCO3 and 18.5 vol % hollow microspheres, and 37 vol % hollow microspheres
- Fig. 3 : Total solar reflectance (TSR) from Fig. 2 (initial and post aging)
- Fig. 4 : Effect of dirt pick-up for carbon black after rinsing with water
- Fig. 5 : Effect of dirt pick-up for carbon black after rinsing with soap and water
- Fig. 6 : Effect of dirt pick-up for red iron oxide after rinsing with water
- Fig. 7 : Effect of dirt pick-up for red iron oxide after rinsing with soap and water
- Fig. 8 : Adherence and wet adherence of coatings on galvanized steel
- Table 1 : TRS and brightness
- Table 2 : Formulations
- Table 3 : Dirt pick-up by coatings (red iron oxide and black carbon)
- Table 4 : Adherence and wet adherence for coatings on galvanized steelEn ligne : https://drive.google.com/file/d/10SyHz10U-DI6omB1IYs-sDzdVvzkCX6d/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31806
in COATINGS TECH > Vol. 16, N° 1 (01/2019) . - p. 20-27[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 20503 - Périodique Bibliothèque principale Documentaires Disponible
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