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Effect of specific additives on the degree of sulfonation and its influence on leather fatliquoring / R. Janardhanan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVII, N° 9 (09/2012)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVII, N° 9 (09/2012) . - p. 279-285 Titre : Effect of specific additives on the degree of sulfonation and its influence on leather fatliquoring Type de document : texte imprimé Auteurs : R. Janardhanan, Auteur ; V. Vijayabaskar, Auteur ; B. S. R. Reddy, Auteur Année de publication : 2012 Article en page(s) : p. 279-285 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Additifs Catalyse par transfert de phase Cuirs et peaux Emulsifiants Mouillage (chimie des surfaces) Potentiel zeta Produits de nourriture du cuir Sulfonation Sulfosuccinates Surfactants Tension superficielle Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Sulfosuccinate type anionic surfactants are classical ingredients for industrial applications. They are of great interest because of their excellent surfactant properties. Fatliquors prepared from sulfosuccinates have been effectively utilized in the leather industry, where the degree of sulfonation of the surfactant plays a crucial role in deciding performance. This paper reports on the study of factors such as the addition of phase transfer catalyst, non-ionic wetting emulsifier and co-solvent on the degree of sulfonation. Emusification power, zeta potential, surface tension and particle size were measured. Reaction conditions were optimized, based on the results. Fatliquors were prepared using different sulfosuccinates and applied on leather. The properties of resultant leathers were studied qualitatively and quantitatively, and SEM studies were carried out for the treated leathers. This work provides a basis for the development of better fatliquoring agents. Note de contenu : - MATERIALS AND METHODS : Materials - Control batch - Experiment 1 (E1 - Addition 5% phase transfer catalyst) - Experiment 2 (E2 - Addition 5% non-ionic emulsifier) - Experiment 3 (E3 - Addition 5% co-solvent) - Application on leather - Characterisation methods - PROPERTIES OF RESULTANT LEATHER - SEM STUDIES - DISCUSSION : Sulfonate content of the surfactants - Effect of co-solvent - Effect of emulsifier - Effect of phase transfer catalyst - Properties of sulfosuccinates - Properties of resultant leathers En ligne : https://drive.google.com/file/d/1fV7HN44YCVqzM67LrDl2HHYBnbANX-r3/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=16058 [article]

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Preparation and characterization of a stable core-shell latex with VAE in the core / Shi Luo in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVII, N° 9 (09/2012)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVII, N° 9 (09/2012) . - p. 286-291 Titre : Preparation and characterization of a stable core-shell latex with VAE in the core Type de document : texte imprimé Auteurs : Shi Luo, Auteur ; Bailing Liu, Auteur Année de publication : 2012 Article en page(s) : p. 286-291 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Acrylate de butyle Caractérisation Copolymère éthylène acétate de vinyle Core-Shell Fourier, Spectroscopie infrarouge à transformée de Latex Lumière -- Diffusion Microscopie électronique en transmission Persulfate d'ammonium Polymérisation en émulsion Styrène Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : A core-shell latex containing Butyl Acrylate (BA) and Styrene (St) in shell, and Vinyl Acetate-Ethylene (VAE) in core was successfully prepared by seeded emulsion polymerization with water as the reaction medium. Several key elements related to the polymerization, including core/shell ratio, BA/St ratio and Ammonium persulfate (APS) dosages were investigated in details. Accordingly, an optimal reaction condition was developed. The synthesized l,atex particles were characterized by Transmission electron microscopy (TEM) and Dynamic light scattering (DLS). The clear core-shell structure and chemical components of the core-shell latex particles were determined by TEM and Fourier transform infrared (FTIR) spectrometry, respectively. In addition, the comparisons between the core-shell latex and VAE latex were made. The experimental results indicated that the developed core-shell latex produced improved leather related properties for thermal stability, water resistance and adhesion. Note de contenu : - MATERIALS - SEEDED EMULSION POLYMERIZATION - CHARACTERIZATION : Solid content and conversion - Stability of the emulsion - Water absorption ratio - Thermogravimetric analysis - Adhesive strength - Infrared spectra - Particle size and morphology - SYNTHESIS CONDITIONS OF THE CORE/SHELL : Core/shell ratio - BA/St ratio - APS dosage - FTIR SPECTRA - LATEX PARTICLE MORPHOLOGY OF CORE-SHELL EMULSION - THERMAL STABILITY ANALYSIS - WATER ABSORPTION OF EMULSION FILMS - ADHESION PERFORMANCE OF EMULSIONS - TABLE I : Recipes for the preparation of core-shell (BA-St-VAE) by seeded emulsion polymerization with various core/shell ratio - TABLE II : Recipes for the preparation of core-shell (BA-St-VAE) by seeded emulsion polymerization with various BA/St ratio - TABLE III : Recipes for the preparation of core-shell (BA-St-VAE) by seeded emulsion polymerization with various content of APS - TABLE IV : The latex stability with various core/shell ratio - TABLE V : The emulsion stability with various BA/St ratio - TABLE VI : The latex stability and polymerization conversion with various APS dosage - TABLE VII : The water absorption ratio and contact angle of latex films - TABLE VIII : The adhesive strength of emulsions En ligne : https://drive.google.com/file/d/1pzeVlxUmYVjPxtCANlg-jhi6qjpX1U-T/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=16059 [article]

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Quality enhancement of low grade wet blue leathers : up-grading of thin substance in the wet end process / K. Gowthaman in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVII, N° 9 (09/2012)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVII, N° 9 (09/2012) . - p. 292-301 Titre : Quality enhancement of low grade wet blue leathers : up-grading of thin substance in the wet end process Type de document : texte imprimé Auteurs : K. Gowthaman, Auteur ; S. Vikram, Auteur ; N. N. Fathima, Auteur ; Jonnalagadda Raghava Rao, Auteur Année de publication : 2012 Article en page(s) : p. 292-301 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux -- Propriétés organoleptiques Qualité -- Contrôle Tannage Wet-blue (tannage) Peau tannée au chrome (le chrome donne une couleur bleue) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Various factors control the quality of the raw materials (hides/skins) used for leather processing. Leathers made from such varied quality of raw materials also have very varied grading. Leathers of higher grades are processed conventionally and finished to the desired effect and the required end product. However, processing and manufacturing of lower grade leathers and improving their properties to make them more useful for high quality products is a big challenge for the leather industry. Conventional up-grading of low quality leathers is brought about by surface modifications. However, such surface modifications significantly affect the natural look of the leathers and hence find use in products applications of low value. This study attempted to improve the grade of the leathers by suitably modifying the post tanning operations without affecting the natural feel of the leathers. One of the major defects, thin substance, has been selected for up-grading. The post tanning auxiliaries have been selected so as to enhance the substance of the leather. Different types of leathers (upper, glove and lining) were made from thin substance raw material. The physical strength properties of these leathers match that of the conventionally processed leathers. The organoleptic properties of the leathers made in this study are also on par with that of the conventional leathers. The cost of chemicals can be easily offset with the additional value realized by following this process of up-grading. Note de contenu : - EXPERIMENTAL : Post tanning operations - Physical testing of leather samples - Evaluation of organoleptic properties - Wet and dry rub fastness - Scanning electron microscopic analysis - RESULTS AND DISCUSSION : Syntans - Fatliquors - Up-grading in thin substance - Physical strenght characteristics, organoleptic properties and rub fastness measurements - TABLE I : Process recipe for upper leather from wet blue this substance - TABLE II : Process recipe for lining leather from wet blue thin substance - TABLE III : Process recipe for glove leather from wet blue thin substance - TABLE IV : Comparison of post tanning chemicals for conventional and experimental upper leathers from wet blue thin substance - TABLE V : Comparison of post tanning chemicals for conventional and experimental lining leathers from this substance - TABLE VI : Comparison of post tanning chemicals used for conventional and experimental glove leathers from wet blue thin substance - TABLE VII : Up-grading achieved for different types of leathers from wet blue thin substance - TABLE VIII : Physical strength characteristics of various leathers made from wet blue thin substance - TABLE IX : Rub fastness characteristics of various leathers made from wet blue thin substance En ligne : https://drive.google.com/file/d/15fJ2XqIbS4KAmKqlT25tLn-FTj0ZMQJR/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=16060 [article]

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Microbiological and near IR studies of leather from hides presoaked in formulations that can remove hardened bovine manure / Mila L. Adelma-Ramos in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVII, N° 9 (09/2012)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVII, N° 9 (09/2012) . - p. 302-310 Titre : Microbiological and near IR studies of leather from hides presoaked in formulations that can remove hardened bovine manure Type de document : texte imprimé Auteurs : Mila L. Adelma-Ramos, Auteur ; Zerlina E. Muir, Auteur ; Daniel K. Y. Solaiman, Auteur ; Suzanne Schreyer, Auteur Année de publication : 2012 Article en page(s) : p. 302-310 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Antimicrobiens Carbonate de sodium Le carbonate de sodium est un composé chimique ayant pour formule Na2CO3. Il s'agit d'un sel de sodium de l'acide carbonique. Dans le langage courant, on parle aussi de soude ou de cristaux de soude, à cause de son contenu en sodium et de sa forme habituellement cristalline. Par contre, il ne faut pas confondre le carbonate de sodium avec la soude caustique ou encore avec le bicarbonate de soude. Dioxyde de chlore Glycérine Le glycérol, ou glycérine, est un composé chimique de formule HOH2C–CHOH–CH2OH. C'est un liquide incolore, visqueux et inodore au goût sucré, utilisé dans de nombreuses compositions pharmaceutiques. Sa molécule possède trois hydroxyles correspondant à trois fonctions alcool responsables de sa solubilité dans l'eau et de sa nature hygroscopique. Un résidu glycérol constitue l'articulation centrale de tous les lipides de la classe des triglycérides et des phosphoglycérides. PROPRIETES PHYSIQUES : Le glycérol se présente sous la forme d'un liquide transparent, visqueux, incolore, inodore, faiblement toxique si ingéré (mais laxatif à haute dose), au goût sucré. Le glycérol peut se dissoudre dans les solvants polaires grâce à ses trois groupes hydroxyles. Il est miscible dans l'eau et l'éthanol ; et insoluble dans le benzène, le chloroforme et le tétrachlorométhane. Son affinité avec l'eau le rend également hygroscopique, et du glycérol mal conservé (hors dessicateur ou mal fermé) se dilue en absorbant l'humidité de l'air. - PROPRIETES CHIMIQUES : Dans les organismes vivants, le glycérol est un composant important des glycérides (graisses et huiles) et des phospholipides. Quand le corps utilise les graisses stockées comme source d'énergie, du glycérol et des acides gras sont libérés dans le sang. - DESHYDRATATION : La déshydratation du glycérol est faite à chaud, en présence d'hydrogénosulfite de potassium (KHSO3) et produit de l'acroléine - ESTERIFICATION : L'estérification du glycérol conduit à des (mono, di ou tri) glycérides. - AUTRES PROPRIETES : Le glycérol a un goût sucré de puissance moitié moindre que le saccharose, son pouvoir sucrant est de 0,56-0,64 à poids égal13. Le glycérol a des propriétés laxatives et diurétiques faibles. Comme d'autres composés chimiques, tels que le benzène, son indice de réfraction (1,47) est proche de celui du verre commun (~1,50), permettant de rendre "invisibles" des objets en verre qui y seraient plongés. Peaux brutes -- Nettoyage Peaux brutes -- Trempe Spectroscopie infrarouge proche Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : New efficient eco-friendly soaking methods are urgently needed to clean manure from raw hides for storage and shipment abroad of the ~35M bovine hides annually produced in USA. High concentrations of surfactant (~0.15% (w/w)) and biocide (~0.10%(w/w)) in commonly used presoaking solution are functional for eliminating microbial contamination, but these are quite unfriendly to the environment and are also inefficient in removing the damaging adobe-type manure. We found that a much lower concentration of surfactant (~0.0375% (w/w) and biocide (~0.025% (w/w) are sufficiently effective when crude glycerol and sodium carbonate are incorporated in the presoaking formulation. Using lower concentrations, the efficiency in removing hardened manure improved and ~70% microbial growth inhibition was still observed. Furthermore, significant manure smell reduction and additional microbial inhibition are observed when chlorine dioxide is also added. No chemical and structural alterations on finished leather samples made from the presoaked hides were observed based on non-denaturing Near Infrared (NIR) spectroscopy analysis. The leather products made from hides that were presoaked in newly developed formulations showed comparable or even better mechanical properties than the control leather products obtained from traditionally treated hides. Considering the low cost in the procurement and the presence of other ingredients in it that have enhanced the efficiency in softening and removing of adobe type manure, crude glycerol is quite desirable as an ingredient in the new eco-friendly presoaking formulation. Note de contenu : - EXPERIMENTAL METHODS : Materials - Soaking/manure removal processes - Microbial growth studies - Near-IR analysis of manure and leather product samples - RESULTS AND DISCUSSION : Soaking/manure processes - Near IR spectra of the leather samples from presoaked hide samples - Microbiological growth inhibition studies - TABLE I : Qualitive comparison of adobe type manure removal from hide sample with manure clinging tightly through the hair. Removal efficiency is directly proportional to the # of X after 2h soaking - TABLE II : Presoaking formulations where only a fraction of the standard soaking formulation was used with varied amounts of other cleansing agents - TABLE III : Presoaking formulations used for microbiological inhibition studies on petri plates En ligne : https://drive.google.com/file/d/1P7qRdnviTrqEHoUAmFPQ5mo5wtnDxdpt/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=16061 [article]

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