Diffusion cell investigations into the acidic degradation of organic coatings / Victor Buhl Møller in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 15, N° 6 (11/2018)  

[article]  inJOURNAL OF COATINGS TECHNOLOGY AND RESEARCH > Vol. 15, N° 6 (11/2018) . - 1201-1215 Titre : Diffusion cell investigations into the acidic degradation of organic coatings Type de document : texte imprimé Auteurs : Victor Buhl Møller, Auteur ; Ting Wang, Auteur ; Kim Dam-Johansen, Auteur ; Sarah Maria Frankaer, Auteur ; Søren Kiil, Auteur Année de publication : 2018 Article en page(s) : 1201-1215 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Acidité Coefficient de diffusion Un coefficient de diffusion est une grandeur caractéristique du phénomène de diffusion de la matière. Le coefficient de diffusion mesure le rapport entre le flux molaire dû à la diffusion moléculaire, et le gradient de concentration de l'espèce chimique considérée (ou, plus généralement, de la variable d'effort entraînant cette diffusion), comme formulé par la loi de Fick. Copolymère vinyle ester Matériaux -- Propriétés barrières Modèles mathématiques Perméation Polyuréthanes Revêtements organiques Revêtements protecteurs -- Détérioration Index. décimale : 667.9 Revêtements et enduits Résumé : Protective organic coatings work by preventing contact between an aggressive environment and a vulnerable substrate. However, the long required lifetime of a barrier coating provides a challenge when attempting to evaluate coating performance. Diffusion cells can be used as a tool to estimate coating barrier properties and lifetime. In this work, a diffusion cell array was designed, constructed, and compared to previous designs, with simplicity being the most important design parameter. Sulfuric acid diffusion through five different coatings was monitored using a battery of cells, and a mathematical model was developed to simulate the experimental data and to study diffusion mechanisms. The diffusion cells allowed an objective and fast analysis of coating barrier properties. It was found that sulfuric acid deteriorated these properties as it diffused through the films. This was also expressed in the modeling results, where a three-step time dependency of the diffusion coefficient was required to simulate both acid breakthrough time and the subsequent steady-state flux. A vinyl ester-based coating proved to be the most effective barrier to sulfuric acid diffusion, followed by a polyurethane coating. Amine-cured novolac epoxies provided the least effective protection. Note de contenu : - PREVIOUS DIFFUSION CELL DESIGN - NEW DIFFUSION CELL DESIGN - DIFFUSION CELL DETAILS - EXPERIMENTAL CONDITIONS - EXPERIMENTAL PROCEDURE - COATINGS INVESTIGATED - MATHEMATICAL MODELING : Mass balance - Estimation of model parameters - EXPERIMENTAL RESULTS : Preliminary conditions - Harsh conditions - MATHEMATICAL MODELING OF DIFFUSION DATA : Using constant diffusion coefficients - Using concentration and time-dependent diffusion coefficients - DISCUSSION : Coating barrier properties - Coating performance and lifetime estimation - Coating degradation and diffusion mechanisms - Water saturation effects - Combined cell mechanism - VALIDATION OF MODEL ASSUMPTIONS DOI : 10.1007/s11998-018-0094-z En ligne : https://link.springer.com/content/pdf/10.1007%2Fs11998-018-0094-z.pdf Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=31331 [article]

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Eco-friendly leather dyeing using ultrasound technique / Mohamed Abu Sayid Mia in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXV, N° 6 (06/2020)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXV, N° 6 (06/2020) . - p. 199-206 Titre : Eco-friendly leather dyeing using ultrasound technique Type de document : texte imprimé Auteurs : Mohamed Abu Sayid Mia, Auteur ; Refat E. Ashraf, Auteur ; Mohammad Nurnabi, Auteur ; Mohamed Zahnagir Alam, Auteur Année de publication : 2020 Article en page(s) : p. 199-206 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse thermique Caractérisation Coefficient de diffusion Un coefficient de diffusion est une grandeur caractéristique du phénomène de diffusion de la matière. Le coefficient de diffusion mesure le rapport entre le flux molaire dû à la diffusion moléculaire, et le gradient de concentration de l'espèce chimique considérée (ou, plus généralement, de la variable d'effort entraînant cette diffusion), comme formulé par la loi de Fick. Colorants -- Absorption Colorants acides Cuirs et peaux -- Propriétés physiques Cuirs et peaux -- Teinture Essais de résilience Essais dynamiques Microscopie électronique à balayage Morphologie (matériaux) Noir (couleur) Résistance à l'abrasion Résistance à la traction Résistance à la transpiration Rouge (couleur) Thermogravimétrie Ultrasons Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In this study, leather was dyed using ultrasound and conventional methods to investigate the influence of ultrasound on leather dyeing. Ultrasound is more effective than mechanical agitation in enhancing leather dyeing. Effects of various process parameters, such as, dyeing temperature, dyeing time and doses of dye on dyeing of leather in presence of ultrasound were investigated. Dyed leathers were characterized with scanning electron microscopy (SEM), photomicrographic analysis, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), etc. It was observed that percentage exhaustion of dye, dye uptake, dye penetration and diffusion coefficient were increased significantly in presence of ultrasound compared to those of dyeing in absence of ultrasound. Moreover, physical properties of the dyed leathers were also investigated. Color rub fastness, perspiration, tensile strength, etc. of dyed leather in presence of ultrasound were higher than that of without ultrasound. SEM analyses of the surface and cross section of the dyed leather showed that fiber structure was not affected by ultrasound. Photomicrographic analysis of cross-section of the dyed leather also showed a deeper penetration of dye in presence of ultrasound. Consequently, dye content in the spent liquor was decreased resulting in a lower environmental pollution. Note de contenu : - EXPERIMENTAL : Materials - Experimental set-up - Dyeing of leather - Analysis of dye uptake and exhaustion - Characterization of dyed leather - RESULTS AND DISCUSSION : FT-IR analysis of dyes used in this study - Effect of time on dye uptake of leather - Percentage exhaustion of dye - Photomicrographic analysis of dyed leather - Diffusion coefficient - Morphology analysis - Thermogravimetric analysis of dyed leather - Differential scanning calorimetric analysis of dyed leather - Physical properties of the dyed leathers - Environmental benefits DOI : https://doi.org/10.34314/jalca.v115i6.3819 En ligne : https://drive.google.com/file/d/1oiP6QwmmA5m9OWcokk8xFuzodx5sP63r/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34321 [article]

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Formaldehyde release from chekiang lambskin, characteristic parameter determination and influencing factors / Hao Dong-Yan in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 103, N° 5 (09-10/2019)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 103, N° 5 (09-10/2019) . - p. 260-267 Titre : Formaldehyde release from chekiang lambskin, characteristic parameter determination and influencing factors Type de document : texte imprimé Auteurs : Hao Dong-Yan, Auteur ; Wang Xue-Chuan, Auteur ; Lu Wei-Na, Auteur ; Li Ji, Auteur Année de publication : 2019 Article en page(s) : p. 260-267 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Coefficient de diffusion Un coefficient de diffusion est une grandeur caractéristique du phénomène de diffusion de la matière. Le coefficient de diffusion mesure le rapport entre le flux molaire dû à la diffusion moléculaire, et le gradient de concentration de l'espèce chimique considérée (ou, plus généralement, de la variable d'effort entraînant cette diffusion), comme formulé par la loi de Fick. Cuirs et peaux de moutons Distillation Emissivité En transfert radiatif, l'émissivité correspond au flux radiatif du rayonnement thermique émis par un élément de surface à température donnée, rapporté à la valeur de référence qu’est le flux émis par un corps noir à cette même température. Cette dernière valeur étant la valeur maximale possible, l'émissivité est un nombre inférieur ou égal à l'unité. (widipedia) Extraction (chimie) Fourrures -- Teneur en formaldehyde Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : VOC emissions may cause poor indoor (vehicle cabins included) air quality (IAQ). Recent studies have been conducted on the characteristics of volatile organic compounds (VOCs) emissions, most of them are focused on wood-based building materials, fur or fur imitations are scarcely mentioned. However, formaldehyde or formaldehyde-containing chemicals are often used in the production of fur, resulting in a certain amount of formaldehyde remaining in the finished product. This paper takes formaldehyde (FA) as an example to study its diffusion in fur. In order to understand and control the behaviour of the formaldehyde emission characteristics. Based on detailed mass transfer analysis of the emission process in a ventilated chamber, this paper measured the three emission characteristic parameters, i.e., the initial emittable concentration (C0), the diffusion coefficient (Dm) and the partition coefficient (K). The influence of different factors on the release parameters was also studied, as well as the time required for the emission of formaldehyde under different ventilation rates ; we also compared the formaldehyde results of different test methods. The results showed that both Dm and C, increased as temperature rose, but Co increase is significant. With the increase of relative humidity, Dm decreased but Co increased. In addition, the prediction model agrees well with the experimental data. The greater the ventilation rate, the faster the improvement of air quality standards in the cabin; The initial concentration was less than 43% of the formaldehyde content obtained through the extraction method and less than 4.6% of the formaldehyde content obtained by the distillation method. Note de contenu : - EXPERIMENTAL PROCEDURE : Materials - Equipment and instruments - Formaldehyde emission test of fur - Extraction method - Distillation method - Mass release model - RESULTS AND DISCUSSION : Effects of different temperatures on the release parameters - The effect of different relative humidity levels on characteristic parameters - Comparison of diffusion coefficient Dm between fur and other materials in the literature - Comparison of release time of formaldehyde in the environmental cabin under different ventilation conditions - Comparison of the initial concentration of fur formaldehyde with the concentration measured by distillation and extraction method - Sensitivity analysis En ligne : https://drive.google.com/file/d/1yku0zJdX5XxuEJ6e7E33dfsg429hja_r/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33001 [article]

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Interdependence of hygroscopic polymer characteristics and drying kinetics during desiccant drying and microwave supported drying / Oliver Kast in INTERNATIONAL POLYMER PROCESSING, Vol. XXXV, N° 4 (08/2020)  

[article]  inINTERNATIONAL POLYMER PROCESSING > Vol. XXXV, N° 4 (08/2020) . - p. 376-384 Titre : Interdependence of hygroscopic polymer characteristics and drying kinetics during desiccant drying and microwave supported drying Type de document : texte imprimé Auteurs : Oliver Kast, Auteur ; Tobias Schaible, Auteur Année de publication : 2020 Article en page(s) : p. 376-384 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Coefficient de diffusion Un coefficient de diffusion est une grandeur caractéristique du phénomène de diffusion de la matière. Le coefficient de diffusion mesure le rapport entre le flux molaire dû à la diffusion moléculaire, et le gradient de concentration de l'espèce chimique considérée (ou, plus généralement, de la variable d'effort entraînant cette diffusion), comme formulé par la loi de Fick. Humidité -- Absorption:Eau -- Absorption Matériaux -- Propriétés hygroscopiques Micro-ondes Polyamides Un polyamide est un polymère contenant des fonctions amides -C(=O)-NH- résultant d'une réaction de polycondensation entre les fonctions acide carboxylique et amine. Selon la composition de leur chaîne squelettique, les polyamides sont classés en aliphatiques, semi-aromatiques et aromatiques. Selon le type d'unités répétitives, les polyamides peuvent être des homopolymères ou des copolymères. Polymères Polymères -- Propriétés thermiques Polymérisation Structure moléculaire Index. décimale : 668.4 Plastiques, vinyles Résumé : Hygroscopic polymers absorb and bind water. If not dried properly, the residual moisture can cause major problems for converting and affect the product quality significantly. Therefore, an effective drying down to an acceptable moisture level is essential for a successful production. Though data sheets give recommendations for drying parameters, these do not consider the actual current moisture up-take of the plastic pellets or the current ambient conditions. This paper investigates the interdependencies of polymer characteristics, like thermal properties and molecular structure, and the drying kinetics of the respective polymers. Tests are carried out with five different polymers on a State-of-the-Art desiccant dryer. The results show that distinctive drying behaviors can be attributed to the molecular structure of the respective plastic. This is reflected by the activation energy according to Arrhenius, the diffusion coefficient and the Flory-Huggins-Parameter, all showing a positive correlation with drying speed and therefore can be used as indicators to estimate drying times. Also, an industrial scale prototype of a microwave enhanced drying system was used to investigate the effect of microwave application on the drying kinetics. Experimental results show potential for reducing the drying times needed, especially for lower temperatures of the drying air and highly hydrophilic plastics. For higher temperatures, however, the prototype could not compete with the state-of-the-art desiccant dryer, due to heat losses and inefficient tubing of the prototype. Considering this, the benefits of microwave application could be shown representatively for polyamide 6 also at higher temperatures. Note de contenu : - INTRODUCTION : Water absorption of hygroscopic polymers - Drying mechanisms of current drying systems - EXPERIMENTAL : Testing materials - Determination of diffusion coefficients - Experimental set-up - Parametric study - EXPERIMENTAL RESULTS : Drying performance - Effects of microwave application - CONCLUDING REMARKS DOI : https://doi.org/10.3139/217.3940 En ligne : https://drive.google.com/file/d/1IfgML_Rufl3kG3uQKCsZPtLrFe1lxk0n/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34696 [article]

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Lime-free unhairing : Part 5. Some peculiarities of dyeing lime-free leather / A. Zaliauskiene in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 90, N° 2 (03-04/2006)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 90, N° 2 (03-04/2006) . - p. 73-79 Titre : Lime-free unhairing : Part 5. Some peculiarities of dyeing lime-free leather Type de document : texte imprimé Auteurs : A. Zaliauskiene, Auteur ; Kestutis Beleska, Auteur ; Virgilijus Valeika, Auteur ; J. Balciuniene, Auteur ; V. Valeikene, Auteur ; V. Tricys, Auteur Année de publication : 2006 Article en page(s) : p. 73-79 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Coefficient de diffusion Un coefficient de diffusion est une grandeur caractéristique du phénomène de diffusion de la matière. Le coefficient de diffusion mesure le rapport entre le flux molaire dû à la diffusion moléculaire, et le gradient de concentration de l'espèce chimique considérée (ou, plus généralement, de la variable d'effort entraînant cette diffusion), comme formulé par la loi de Fick. Colorants Cuirs et peaux -- Teinture Hydrophobie Pénétration (physique) Rouge (couleur) Thermodynamique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The interaction of leather, prepared by the lime-free method, and a series of 1:2 metal complex dyes has been investigated by determining the distribution of the dyes at equilibrium. Kinetic and thermodynamic aspects such as the rate of dyeing, heat of dyeing, entropy, affinity of dyes on the lime-free and conventional leather have been studied. The diffusion coefficient was calculated by means of the Weisz pore and Krenk models. It has been established that the sorption isotherms for these dyes on both types of leather fibres show a Langmuir type of behaviour. The dyeing system hydrophobic C.I. Acid Red 247/lime-free leather has a positive heat of dyeing: dyeing is an endothermic process in this case. The change of entropy of interaction of hydrophobic C.I. Acid Red 247 and leather fibres is 24 cal/mol•K. An increased degree of freedom should be associated with water molecules such as those hydrating the dye and the fibre, and possibly, due to randomness in the fibre itself. This decreased degree of the order of water molecules results in a positive change of entropy, which then is the thermodynamic cause of the hydrophobic bonding. The influence of factors such as, initial amount of dye, pH of leather and temperature on the dyeing process was established. The results have shown that lime-free leather absorbs lesser amounts of dye during dyeing but that, the dye penetrates more deeply compared with conventional leather. The amount of dye, pH and temperature has no influence on such a tendency. On the other hand, the investigation has shown that the factors mentioned have a more marked influence on the progress of dyeing of lime-free leather compared with dyeing conventional leather. This means that inconsiderable deviation from determined parameters of dyeing can markedly deteriorate the quality of the dyed leather. The data obtained have confirmed that the change in the method of liming considerably influences subsequent processes in leather processing. Note de contenu : - EXPERIMENTAL PROCEDURE : Leather samples for dyeing - The preparation of leather fibres for dyeing - Dyes and dyeing - Determination of hydrophobicity of dyes - Determination of depth of dye penetration into leather - Investigation of dyeing kinetics - Thermodynamic investigation of dyeing - RESULTS AND DISCUSSION : Kinetic and thermodynamic investigation - Investigation of dyeing parameters on the progress of dyeing - Table 1 : Indexes of pelt and leather obtained by use of lime-free and conventional unhairing - Table 2 : The dependence of diffusion coeffficient on unhairing method - Table 3 : The thermodynamic characteristic of dyeing process En ligne : https://drive.google.com/file/d/16mWq3L-c0sNpayWDNSSXPgzVTvU4htbU/view?usp=share [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39160 [article]

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Properties of shoe leathers and their measurement / H. Bradley in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. LXI (Année 1966)  

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The role of the finish in affecting leather comfort / Mortimer Greif in JOURNAL OF THE SOCIETY OF LEATHER TRADES' CHEMISTS, Vol. 54, N° 3 (03/1970)

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The use of Monte Carlo simulation to evaluate the optical properties of polyester fabric treated with titanium dioxide nanopigments / Laleh Asadi in COLORATION TECHNOLOGY, Vol. 139, N° 1 (02/2023)  

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Thermodynamic and kinetic studies of the adsorption behaviour of the natural dye cochineal on polyamide 66 / Mousa Sadeghi-Kiakhani in COLORATION TECHNOLOGY, Vol. 134, N° 4 (08/2018)  

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A tunable controlled-release urea fertilizer coated with a biodegradable polyurethane-nanoclay composite layer / Kannika Sitthisuwannakul in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 20, N° 2 (03/2023)  

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Use of MieLab software in scattering calculations / Daniel C. Kraiter in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 19, N° 6 (11/2022)  

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Water vapor transmission properties of acrylic organic coatings / Réka Lilla Kovács in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 18, N° 2 (03/2021)  

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