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Titre : Universal concentrate Type de document : texte imprimé Année de publication : 2007 Article en page(s) : p. 26-28 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Aluminium L'aluminium est un élément chimique, de symbole Al et de numéro atomique 13. C’est un métal pauvre, malléable, de couleur argent, qui est remarquable pour sa résistance à l’oxydation13 et sa faible densité. C'est le métal le plus abondant de l'écorce terrestre et le troisième élément le plus abondant après l'oxygène et le silicium ; il représente en moyenne 8 % de la masse des matériaux de la surface solide de notre planète. L'aluminium est trop réactif pour exister à l'état natif dans le milieu naturel : on le trouve au contraire sous forme combinée dans plus de 270 minéraux différents, son minerai principal étant la bauxite, où il est présent sous forme d’oxyde hydraté dont on extrait l’alumine. Il peut aussi être extrait de la néphéline, de la leucite, de la sillimanite, de l'andalousite et de la muscovite.
L'aluminium métallique est très oxydable, mais est immédiatement passivé par une fine couche d'alumine Al2O3 imperméable de quelques micromètres d'épaisseur qui protège la masse métallique de la corrosion. On parle de protection cinétique, par opposition à une protection thermodynamique, car l’aluminium reste en tout état de cause très sensible à l'oxydation. Cette résistance à la corrosion et sa remarquable légèreté en ont fait un matériau très utilisé industriellement.
L'aluminium est un produit industriel important, sous forme pure ou alliée, notamment dans l'aéronautique, les transports et la construction. Sa nature réactive en fait également un catalyseur et un additif dans l'industrie chimique ; il est ainsi utilisé pour accroître la puissance explosive du nitrate d'ammonium.
Colorimétrie
Ethoxylate d'alkylphénol
Nonylphenol éthoxylates
Oxyde de fer
Pigments métalliques
Produits chimiques -- Suppression ou remplacement
RhéologieIndex. décimale : 667.2 Colorants et pigments Résumé : This article is about the development of an APE replacement for use as dispersing additives for transparent iron oxides and aluminium pigments. More than 40,000t of alkylphenolethoxylates (APEs) are produced annually. They are highly versatile and therefore used in the most diverse applications such as detergents, plastics and in the agrochemicals and coatings industries. In the latter, alkylphenolethoxylates are employed in the manufacture of universal pigment concentrates. These are waterborne formulations for colouring waterborne and solventborne base paints. The use of such universal pigment concentrates is state-of-the-art but the use of alkylphenolethoxylates (mainly nonylphenolethoxylates, [NPE]) is, for many reasons, questionable. The most serious is certainly the threat to water posed by nonylphenol, a decomposition product of nonylphenolethoxylate, which is formed as soon as NPE reaches the environment and thus waste water. Nonylphenol is similar to the female hormone, 17-β-oestradiol. The intervention of such decomposition products in the reproduction cycles of fish and mammals is considered proven. Moreover, even low concentrations of nonphenol are toxic to aquatic life. Despite these serious ecological problems and related regulatory controls, replacing nonylphenolethoxylates in universal pigment concentrates has proved difficult and lengthy due to the almost complete lack of suitable alternatives. Pigment concentrates based on transparent iron oxide and slurries of aluminium pigments pose a particular challenge. Note de contenu : - Nonylphenolethoxylate and ionic derivates
- Risk-free aromatic ring-containing structures
- Tested formulations
- Rheology
- Colourimetric tests
- Further development
- Transparent iron oxides
- FIGURES : 1. Comparison of 17-,oestradiol with nonylphenol - 2. Non-ionic NP structure and isphosphate derivative - 3. Phosphate with a polyether containing styrene oxide - 4. Viscosity profiles of iron oxide red concentrates - 5. Typical results in a waterborne acrylic emulsion and in a solvent borne alkyd paint
- TABLES : 1. Tested formulations - 2. Results with iron oxides - Sample formulation with transparent iron oxidesEn ligne : https://drive.google.com/file/d/1BqTnQdSKGNXbH4Pq1f9uxDAgXdWe0zNb/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27417
in POLYMERS PAINT COLOUR JOURNAL - PPCJ > Vol. 197, N° 4510 (03/2007) . - p. 26-28[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 006367 - Périodique Bibliothèque principale Documentaires Disponible Use of novel polyetheralkanolamine comb polymers as pigment dispersants for aqueous coating systems / Nguyên-Dang-Tâm in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 4, N° 3 (09/2007)
[article]
Titre : Use of novel polyetheralkanolamine comb polymers as pigment dispersants for aqueous coating systems Type de document : texte imprimé Auteurs : Nguyên-Dang-Tâm, Auteur Année de publication : 2007 Article en page(s) : p. 295-309 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Agents dispersants (chimie)
Chimie des surfaces
Colorimétrie
Pigments
Revêtements en phase aqueuse:Peinture en phase aqueuse
RhéologieIndex. décimale : 667.9 Revêtements et enduits Résumé : The adsorption of a series of polyetheralkanolamine comb polymers characterized by a different length of the hydrophilic tail has been investigated at the carbon black/water interface by measuring adsorption isotherm, contact angle, wetting rate, zeta potential, and particle size distribution. Zeta potential measurements and adsorption layer thickness results suggest that polyetheralkanolamines with high ethylene oxide (EO) content provide only steric stabilization and they adsorb at the interface with the ethylene oxide chains in a coil conformation. The thickness of the adsorbed layer increases with increasing EO units; however, the surface tension and interfacial tension decrease with increasing EO content. Adsorption isotherms show that most of the added polyetheralkanolamine adsorbs onto the carbon black and only a small amount stays in the water phase. When treated with a polyetheralkanolamine, carbon black dispersions show uniform (unimodal) and narrow particle size distribution with very small median sizes of about 0.10 µm. The pigment concentrates containing the polyetheralkanolamine show excellent color compatibility in various decorative commercial white paints containing a wide range of resins and exhibit low viscosity with nearly Newtonian flow behavior. DOI : 10.1007/s11998-007-9027-y En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-007-9027-y.pdf Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3645
in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 4, N° 3 (09/2007) . - p. 295-309[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 008270 - Périodique Bibliothèque principale Documentaires Disponible Use of a predictive colour model for managing the colour appearance of two-colour woven fabrics / Krste Dimitrovski in COLORATION TECHNOLOGY, Vol. 136, N° 3 (06/2020)
[article]
Titre : Use of a predictive colour model for managing the colour appearance of two-colour woven fabrics Type de document : texte imprimé Auteurs : Krste Dimitrovski, Auteur ; Andreja Grmek, Auteur ; Helena Gabrijelcic Tomc, Auteur Année de publication : 2020 Article en page(s) : p. 270-287 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Colorimétrie
Couleur
Prévision, Théorie de la
Spectrophotométrie
Textiles et tissus
Tissés bicolores
vision des couleursIndex. décimale : 667.3 Teinture et impression des tissus Résumé : The aim of this study was to implement a two-dimensional colour appearance model for prediction of the colour values of weft threads when the optical mixing of a two-colour woven structure had to match the colour appearance of a single-colour reference woven fabric. Five single-colour woven fabrics were woven from five threads of similar hue. One of the samples was chosen as a reference, for which the colour appearance was the goal to be achieved in the two-colour woven fabrics prepared with the other available warp threads and newly dyed weft threads. The colour values of dyed weft threads were predicted by a two-dimensional colour appearance model. With dyed weft threads, managing the colour appearance of the two-colour woven fabric was enabled to achieve the colour values of the reference. In the results, colour deviations between the predicted and measured colour values of weft threads revealed some limitations to the colour appearance model and performance of the dyeing process. After the production of the two-colour woven fabric, the colour appearance matched the appearance of the reference, resulting in deviations of ΔE CMC(2:1) = 1.2-7.8. Moreover, the differences between theoretically predicted and measured colour values of the two-colour woven fabric were evaluated as small, ranging from ΔE CMC(2:1) = 1.5-1.9. The results demonstrated the efficiency of implementing the colour appearance model and the dyeing process of weft threads as an approach to achieve the defined colour appearance of two-colour woven fabrics, which with small colour deviations matches the colour of a single-colour reference. Note de contenu : - INTRODUCTION : Colour appearance, combination of differently coloured threads and colour contrast - Theoretical predictions of colour appearance of multicoloured woven structures
- EXPERIMENTAL : Constructional properties of threads and colorimetric measurements - Analysis of two-colour woven fabrics - Dyeing of weft threads with predicted colour values and spectrophotometric measuring of dyed weft threads
- RESULTS AND DISCUSSION : Comparison between the predicted and measured colour appearance of dyed weft threads - Measuring CIELab values and evaluating theoretical colour predictions of two-colour woven fabricsDOI : https://doi.org/10.1111/cote.12458 En ligne : https://onlinelibrary.wiley.com/doi/epdf/10.1111/cote.12458 Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34300
in COLORATION TECHNOLOGY > Vol. 136, N° 3 (06/2020) . - p. 270-287[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 21787 - Périodique Bibliothèque principale Documentaires Disponible Valorization of pomegranate peel waste as retanning agent in leather industry and investigation of its effect on prevention of Cr(VI) formation / Cigdem Kilicarislan Ozkan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVIII, N° 2 (02/2023)
[article]
Titre : Valorization of pomegranate peel waste as retanning agent in leather industry and investigation of its effect on prevention of Cr(VI) formation Type de document : texte imprimé Auteurs : Cigdem Kilicarislan Ozkan, Auteur Année de publication : 2023 Article en page(s) : p. 51-58 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Agents de tannage
Antioxydants
Chrome trivalent -- Oxydation
Colorimétrie
Ecorces
Grenade (fruit) et constituants
Phénols
RetannageIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Although Cr(VI) is not used in any step of the manufacturing process, the entity of Cr(VI) in leather and leather products has become a concern in the leather industry. Formation of free radicals may bring about conditions for the oxidation of free Cr(III) (if exists in leather) to Cr(VI) and these oxidations are usually catalyzed by heat and UV radiation. Antioxidants have an important role in order to inhibit oxidant compound activity by donating an electron to compounds. There are many studies on the prevention of Cr(VI) formation in leather production. The inhibiting properties of Cr(VI) formation were usually investigated by using commercial vegetable tannins (polyphenols) together with other retanning agents in retanning process. However, no study has been conducted on the possible use of pomegranate peel tannins as an alternative retanning agent, which is known as an important source of antioxidants, in leather making and their ability to prevent Cr(VI) formation. In the present study, pomegranate peels were extracted in different solvents and total phenolic content and antioxidant power of the extracts were determined by Folin-Ciocalteu, FRAP (The Ferric Reducing Ability of Plasma) and TEAC/ABTS (Trolox-Equivalent Antioxidant Capacity/2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) methods. Furthermore, different amounts of pomegranate peel extracts were used in retanning processes and the leathers were investigated in terms of increases in thickness, color changes as well as effect on prevention of Cr(VI) formation. The results revealed that besides noticeable retanning performance, pomegranate peel extract has a spectacular effect on prevention of Cr(VI) formation as compatible with its antioxidant power. Note de contenu : - MATERIALS AND METHODS : Materials - Methods : Determination of moisture content of pomegranate peels - Preparation of extracts - Determination of maxiumm extractable materials (MEM) from pomegranate peels - Determination of extraction yields and tannin contents of extract solutions - Total phenols and antioxidant powers of pomegranate peels - Usage of extract solutions in retanning process - Post-retanning tests : Determination of filling coefficient - Determination of color changes - Artificial ageing of leather samples and Cr (VI) analysis
- RESULTS AND DISCUSSION : Moisture content, extraction yields and tannin contents of pomegranate peels - Total phenolic contents and antioxidant powers of pomegranate peels - Filling coefficient and color changes of retanned leathers - Cr(VI) contents of leather samples
- Table 1 : Retanning recipe
- Table 2 : The effect on extraction yields and tannin contents of different extractiontemperatures
- Table 3 : Total phenolic contents and antioxidant powers of pomegranate peels extracted in different solvents
- Table 4 : Filling coefficient values of retanned leathers
- Table 5 : Color measurement values of leathers retanned with pomegranate peel extracts at different ratios before and after ageingDOI : https://doi.org/10.34314/jalca.v118i2.6499 En ligne : https://drive.google.com/file/d/1XYA9ZHyQTB86dburXGWvLZtuqaKtswF0/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38811
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVIII, N° 2 (02/2023) . - p. 51-58[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 23871 - Périodique Bibliothèque principale Documentaires Disponible Vector-based modelling of colour difference : a pilot study of the DE2000 colour difference model / David P. Oulton in COLORATION TECHNOLOGY, Vol. 133, N° 1 (02/2017)
[article]
Titre : Vector-based modelling of colour difference : a pilot study of the DE2000 colour difference model Type de document : texte imprimé Auteurs : David P. Oulton, Auteur ; Stephen Westland, Auteur Année de publication : 2017 Article en page(s) : p. 15–25 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Colorimétrie
Couleur
Couleur -- AnalyseIndex. décimale : 535.6 Couleur Résumé : A novel approach to colour difference modelling is presented whereby for any given CMC (1:1) or CIE DE2000 ?E, ?C, ?H, and ?L colour difference, the equivalent CIE XYZ, L*a*b*, and L*C*h coordinate changes are derived by optimising the input RGB stimuli from which they are all calculated. Single-dimension L or C or H difference loci expressed in DE2000 difference units are thus generated, and the additive equivalence of tristimulus values is likewise projected forward onto each locus and also onto a set of CIE DE2000 three-unit ellipse boundaries. Using the datasets thus generated, it is then shown firstly that the derived ellipses have well-defined semi-axes, which explain the detailed orientation of the MacAdam ellipses in x,y,Y space. Unit CIE DE2000 difference is confirmed as a successful quantifying constant of visual difference over a wide range of chroma, hue, and lightness differences. As a constant, CIE DE2000 unit difference is shown to have a significantly variable value at high and low chroma: evidence is established for systematic changes in both chroma and hue difference sensitivity. A hitherto unresolved non-linearity is revealed in the C* dimension of L*C*h space that is not replicated in the CIE DE2000 model. The derived difference loci appear to specify physically reproducible experimental stimuli that could be used in the estimation of visual difference magnitude. Overall, the data derived by the new approach and presented in this paper increase the probability that a true vector model of the visual difference response may eventually be derived. Note de contenu : - METHODS : The presented analysis - The additivity of spectral stimuli
- RESULTS AND ANALYSIS : The scalar and additive visual response to spectral stimuli - Ellipse orientation - Cylindrical/polar difference vs Cartesian difference scaling - Generating a continuous metric of colour difference - Lightness differenceDOI : 10.1111/cote.12242 En ligne : https://drive.google.com/file/d/1tKvnbXUwl3t71ZTJP9lzkQGpiK1Ci5zF/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27876
in COLORATION TECHNOLOGY > Vol. 133, N° 1 (02/2017) . - p. 15–25[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 18636 - Périodique Bibliothèque principale Documentaires Disponible Vision et mesure de la couleur / Paul Kowaliski / Paris : Masson (1978)
PermalinkVisual sensibility evaluation of Korean traditional indigo-dyed lyocell fabrics / Eugene Lee in COLORATION TECHNOLOGY, Vol. 134, N° 4 (08/2018)
PermalinkWeather-fast colours / Larry G. Lane in POLYMERS PAINT COLOUR JOURNAL - PPCJ, Vol. 196, N° 4502 (07/2006)
PermalinkWet-pink leathers-zirconium-THPS tannage / N. Nishad Fathima in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 91, N° 4 (07-08/2007)
PermalinkPermalinkWhy accurate colour matching needs to control for gloss / Jason Loehr in POLYMERS PAINT COLOUR JOURNAL - PPCJ, Vol. 209, N° 4655 (10/2019)
PermalinkXanthoproteic reaction for the evaluation of wool antifelting treatments / Gianluca Migliavacca in COLORATION TECHNOLOGY, Vol. 130, N° 5 (10/2014)
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