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JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) . Vol. CIX, N° 12Mention de date : 12/2014Paru le : 10/12/2014 |
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Ajouter le résultat dans votre panierPreparation and characterization of collagen grafted by styrene-butyl acrylate and its application for paper sizing / Sufeng Zhang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 12 (12/2014)
[article]
Titre : Preparation and characterization of collagen grafted by styrene-butyl acrylate and its application for paper sizing Type de document : texte imprimé Auteurs : Sufeng Zhang, Auteur ; Qun Wang, Auteur ; Wanwan Dou, Auteur ; Wang Xuechuan, Auteur ; Qiang Taotao, Auteur Année de publication : 2014 Article en page(s) : p. 404-410 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Caractérisation
Collagène
Copolymère styrène acrylate de butyle
Déchets industriels -- Recyclage
Encollage
Greffage (chimie)
Papier
Tannage -- DéchetsIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Collagen extracted from tannery wastes was modified by grafting it with molecular chains formed by polymerizing vinyl and acrylate monomers. The novel collagen product obtained in this manner was tested as paper sizing agent. The structure and properties of modified collagen were characterized by FTIR, STA and XRD. Results indicate that polyvinyl chains were grafted onto collagen, primarily in its crystalline regions. This modification significantly improved the thermal stability of collagen. Then the modified collagen emulsion alone (MCE), or combined either with gelatinized starch (MCE+S) or commercially produced styrene-acrylic emulsion (MCE+SAE), was applied to the surface of corrugating medium. The properties of these products were compared with those of commercially produced medium sized by SAE+S. Sizing by (MCE+S) increased the ring crush index by 12.7% and tensile index by 13.4%. In a Cobb60 test the corrugating medium sized by a blend of modified collagen and styrene acrylic emulsion (MCE+SAE) absorbed less water than commercially produced medium sized by SAE+S. Note de contenu : - Characterization of modified collagen sizing agent
- The sizing properties of modified collagen
En ligne : https://drive.google.com/file/d/1RiMCTbSZlYWnuBvVJIxJWfzJBMaXdwuo/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=22497
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Code-barres Cote Support Localisation Section Disponibilité 16713 - Périodique Bibliothèque principale Documentaires Disponible Cool glove leathers made using thermoresponsive syntans / A. Jaya Prakash in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 12 (12/2014)
[article]
Titre : Cool glove leathers made using thermoresponsive syntans Type de document : texte imprimé Auteurs : A. Jaya Prakash, Auteur ; M. Ragul, Auteur ; Jonnalagadda Raghava Rao, Auteur ; N. N. Fathima, Auteur Année de publication : 2014 Article en page(s) : p. 411-417 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Caractérisation
Copolymère mélamine-Formaldéhyde
Encapsulation
Gants
Matériaux thermosensibles
Syntans
Transition de phaseEn physique, une transition de phase est une transformation du système étudié provoquée par la variation d'un paramètre extérieur particulier (température, champ magnétique...).
Cette transition a lieu lorsque le paramètre atteint une valeur seuil (plancher ou plafond selon le sens de variation). La transformation est un changement des propriétés du système.Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Protection is the main function of gloves; also comfort of the wearer has to be kept in mind while making gloves without compromising on strength and flexibility. Body dissipates heat in the form of sweat; sweating through hands is likely to be more while using gloves in relatively hot weather conditions resulting in discomfort and slipperiness. In order to overcome these problems there is a need for development of materials, which can respond to temperature changes providing comfort and protection. In our current study, Phase Changing Material (PCM) was encapsulated in condensate polymers of melamine formaldehyde for preparation of thermoresponsive syntan. The syntan was characterised using different techniques such as Differential Scanning Calorimetry (DSC), Thermo Gravimetric Analysis (TGA) and Scanning Electron Microscopy (SEM). Glove leathers made using this syntan were termed “Cool glove leathers” as they showed thermoresponsive behaviour, which exhibited a temperature difference of 1.5±0.5°C to that of control leather samples with 0.5±0.4°C. The cool glove leathers were tested for various properties like strength, organoleptic and thermoresponsive function. Note de contenu : - EXPERIMENTAL SECTION : Reagents - Synthesis of PCM microencapsulated melamine-formaldehyde syntan - Characterization of thermoresponsive syntan and leather
- RESULTS AND DISCUSSION : Characterization of PCM based syntan - Characterization of cool glove leathers - Thermo responsive function analysis - Physical strength and organoleptic properties of leathersEn ligne : https://drive.google.com/file/d/1VJhUyzON_eUquxOnyVno4yYI5qHeNPUr/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=22498
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Code-barres Cote Support Localisation Section Disponibilité 16713 - Périodique Bibliothèque principale Documentaires Disponible Elucidation of probable mechanism for biocidal resistance in skin-borne Bacillus Subtilis / S. Kavitha in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 12 (12/2014)
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Titre : Elucidation of probable mechanism for biocidal resistance in skin-borne Bacillus Subtilis Type de document : texte imprimé Auteurs : S. Kavitha, Auteur ; B. Swarnakumari, Auteur ; Chandra Babu Narasimhan Kannan, Auteur ; M. Vahini, Auteur ; C. Vandhana, Auteur Année de publication : 2014 Article en page(s) : p. 418-424 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Antimicrobiens
Bacillus subtilis
Cuirs et peaux
Résistance aux antimicrobiensIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : An attempt has been made in the present investigation to determine the probable mechanism through which a skin-borne bacterium Bacillus subtilis might develop resistance against a dithiocarbamate based biocide. Changes occurring in the cell wall constituents and morphology in the cells grown at sub-optimal level concentrations of biocide were studied based on which the probable mechanism of buildup of biocidal resistance has been proposed. There has been considerable change/reduction in cell wall constituents, peptidoglycan, diaminopimelic acid and teichoic acid due to the presence of biocides. By propidium iodide staining technique, the cell wall permeability has also been found to be reduced. The morphology of the cells as studied using scanning electron microscopy reveals that there is a shortening of rod shape of the cells due to the action of the biocide. Based on the results of the study, it is proposed that the skin-borne Bacillus subtilis encountered in leather processing might develop resistance through changes in the cell wall constituents and reduction in the cell wall permeability. Note de contenu : - MATERIALS AND METHODS : Organism - Biocide - Determination of MIC - Growth study - Preparation of cell wall - determination of PG content - Determination of teichoic acid - Determination of DAP content - Propidium iodide staining - Scanning electron microscope (SEM) analysis
- RESULTS ANS DISCUSSION : Growth study - Cell wall analysis - Propidium iodide staining - Scanning electron microscopic (SEM) analysisEn ligne : https://drive.google.com/file/d/1WZs0BeL6WK9VvBJ6bnZzE2tLJoq6IPli/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=22499
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Code-barres Cote Support Localisation Section Disponibilité 16713 - Périodique Bibliothèque principale Documentaires Disponible Microbial keratinase and its potential application in th management of tannery hair waste / Arthur Onyuka in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 12 (12/2014)
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Titre : Microbial keratinase and its potential application in th management of tannery hair waste Type de document : texte imprimé Auteurs : Arthur Onyuka, Auteur ; Margaret Bates, Auteur ; Anthony D. Covington, Auteur ; A. Paula M. Antunes, Auteur Année de publication : 2014 Article en page(s) : p. 425-430 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Bactéries -- Identification
Biodégradation
Compostage
Cuirs et peaux -- Déchets -- Recyclage
Déchets industriels -- Recyclage
Kératinases
kératineLa kératine est une protéine, synthétisée et utilisée par de nombreux êtres vivants comme élément de structure, et également l'exemple-type de protéine fibreuse.
La kératine est insoluble, et peut être retrouvée sur l'épiderme de certains animaux, notamment les mammifères, ce qui leur garantit une peau imperméable. Parfois, lors d'une friction trop importante, la kératine se développe à la surface de la peau formant une callosité. Les cellules qui produisent la kératine meurent et sont remplacées continuellement. Les morceaux de kératine qui restent emprisonnés dans les cheveux sont couramment appelés des pellicules.
La molécule de kératine est hélicoïdale et fibreuse, elle s'enroule autour d'autres molécules de kératine pour former des filaments intermédiaires. Ces protéines contiennent un haut taux d'acides aminés à base de soufre, principalement la cystéine, qui forment un pont disulfure entre les molécules, conférant sa rigidité à l'ensemble. La chevelure humaine est constituée à 14 % de cystéine.
Il y a deux principales formes de kératines : l'alpha-kératine, ou α-keratin, présente chez les mammifères notamment, dont l'humain, et la bêta-kératine, ou β-keratin, que l'on retrouve chez les reptiles et les oiseaux. Ces deux types de kératines ne présentent clairement pas d'homologie de séquence.
Chez l'être humain, la kératine est fabriquée par les kératinocytes, cellules se trouvant dans la couche profonde de l'épiderme. Les kératinocytes absorbent la mélanine (pigment fabriqué par les mélanocytes), se colorent et ainsi cette pigmentation de l'épiderme permet de protéger les kératinocytes des rayons ultraviolets du Soleil.
Poils -- RecyclageIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : Up to 40 tons of solid hair waste can be generated during the industrial leather manufacturing process posing disposal problems. Composting is considered a viable technology to recycle the hair waste for application in agriculture. However, due to its constituent protein, keratin hair is remarkably resistant to degradation under natural conditions. The aim of this study was to isolate keratin degrading bacteria and evaluate their ability to degrade hair as a preliminary study towards developing a biocatalyst to improve hair degradation during composting. Subsequently, a keratinolytic microorganism was isolated from a nutrient alkaline culture (pH 11) with bovine hair as the source of carbon and nitrogen. The microorganism, identified as belonging to the Bacillus species grew optimally in the temperature range of 40 – 50°C. The partially purified microbial keratinase exhibited broad substrate specificity at pH range 7.5 – 10. The pH and temperature of optimum activity was determined at 9.0 and 50°C, respectively. Scanning electron microscopy assessment of the hair samples showed complete fragmentation of the structure after incubation with the microbial keratinase. Hence, the microbial keratinase has greater potential application as inoculant to enhance biodegradation of tannery solid hair waste during the composting process. Note de contenu : - EXPERIMENTAL METHODS : Microbial growth culture, identification and optimization of growth conditions - Extraction and partial purification of the microbial keratinolytic enzymes - Determination of the protein concentration - Assay for keratinase activity - Assay for proteolytic activity - Determination of pH and temperature for optimum activity - Inhibition studies on the isolated microbial enzyme - Laboratory study on microbial enzyme degradation of bovine hair
- RESULTS AND DISCUSSION : Microbial growth and identification - Keratinolytic and proteolytic activity - Laboratory degradation of bovine hair by the microbial crude enzymeEn ligne : https://drive.google.com/file/d/18Eb6rk5_zdKFHT8jtctNZ_UPix32uPuP/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=22500
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Code-barres Cote Support Localisation Section Disponibilité 16713 - Périodique Bibliothèque principale Documentaires Disponible
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Code-barres | Cote | Support | Localisation | Section | Disponibilité |
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16713 | - | Périodique | Bibliothèque principale | Documentaires | Disponible |