Dépouillements

Molecular modeling approach to vegetable tanning : Preliminary results for gallotannin interactions with the collagen microfibril / Eleanor M. Brown in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVI, N° 5 (05/2011)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVI, N° 5 (05/2011) . - p. 145-152 Titre : Molecular modeling approach to vegetable tanning : Preliminary results for gallotannin interactions with the collagen microfibril Type de document : texte imprimé Auteurs : Eleanor M. Brown, Auteur ; Dennis C. Shelly, Auteur Année de publication : 2011 Article en page(s) : p. 145-152 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Collagène Gallo-tanins Molécules -- Modèles Tannage végétal Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Tanning of animal hides produces leather, a durable, flexible material that is stabilized against putrefaction. Chrome-tanned wet blue, aldehyde crosslinked wet white, and vegetable tanned hides are major contributors to current leather production. Although the chemistries involved are significantly different, the product in each case is leather. Vegetable tanning, the oldest of these technologies is, from a mechanistic perspective, the least well understood. To explore possible vegetable tanning mechanisms, we have applied molecular modeling techniques to the study of interactions of gallotannin, a component of chestnut tannins, with the collagen microfibril. A model gallotannin molecule was constructed and energy minimized. This model was docked into several energetically favorable positions on a fragment of the ERRC collagen microfibril model, generally with a good fit at a proline or hydroxyproline residue. The alpha carbon backbone of collagen was kept immobile during molecular dynamics simulations at 400 - 800K with and without an added layer of water for solvation to identify possibly more favorable interactions sites for the gallotannin molecules. Both inter and intra chain interactions were possible, and several potential sites for hydrogen bonding via arginine residues or hydrophobic interactions with alanine or isoleucine residues were identified. The information gained from this model study is an early step in the development of a vegetable-tanning model. En ligne : https://drive.google.com/file/d/14XNgkdoHQ2WDtRyvAroa1nHsL2Ld5aVp/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11588 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
012969	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Tailor-made biomaterials from collagenic wastes in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVI, N° 5 (05/2011)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVI, N° 5 (05/2011) Titre : Tailor-made biomaterials from collagenic wastes Type de document : texte imprimé Année de publication : 2011 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Biopolymères Collagène Cuirs et peaux Extraction (chimie) Récupération (Déchets, etc.) Recyclage (déchets, etc.) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The production of biopolymers from leather waste is an important and notable process on the tanning waste management research. The basic aim of the present work is the conversion of non-tanned solid wastes from the tanning industry (splits, defective hides) into high added value biopolymers. Those collagenic biomaterials are at the forefront of potential new applications in tissue engineering within fields such as cosmetics, medicine or veterinary. This treatment will entail a great progress in both environmental and economical terms. The first stage of the project was centered on finding, through a factorial experimental design, the most suitable treatment for the isolation of biopolymers. The effect of variables such as: level of grinding (surface area for chemical interaction); chemical treatment (acid, alkaline and neutral medium); time; temperature and agitation, were studied. Those extracted biomaterials could be formulated according to future application as gel, film, sponge or fibers. All the biopolymers obtained through this process were characterized in order to ascertain the significance of the variables studied. “Tailor-made” biopolymers will be designed, with the desired molecular weight, polymorphic formulation (form), optimized properties and characteristics, that is, perfectly adapted to their future applications. Note de contenu : - METHODS : Biopolymer extraction - Film formation - Sponge formation (lyophilisation) - Yield - Swelling - Gel strength - Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) - RESULTS AND DISCUSSION : Study 1. Effect of grinding - Study 2. Effect of agitation (around the optimum) - Biopolymer (optimum) - Biopolymer polymorphic formulations En ligne : https://drive.google.com/file/d/1TpE_1DNgxcoGpGlTmFapZkkiifMelxVv/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11589 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
012969	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Preparation of organosilicone modified palm oil fatliquor / Chen Wang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVI, N° 5 (05/2011)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVI, N° 5 (05/2011) . - p. 161-169 Titre : Preparation of organosilicone modified palm oil fatliquor Type de document : texte imprimé Auteurs : Chen Wang, Auteur ; Shengyu Feng, Auteur ; Jun Wu, Auteur Année de publication : 2011 Article en page(s) : p. 161-169 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Huile de palme et constituants Organosilicones Produits de nourriture du cuir Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Fatliquoring is an important process in leather manufacture and these fatliquors are mainly chemical modification products of animal and vegetable oils. Palm oil, owing to its main characteristics and fatty acid composition is suitable as a raw material for fatliquor preparation. And organosilicone is increasingly used for leather production due to its excellent properties. In this paper, the organosilicone modified palm oil fatliquor was synthesized by amidation with diethanolamine, grafting with hydroxyl-terminated organosilicone, esterification with maleic anhydride and sulfiting with sodium bisulfite, in turn. The influence of the mass percentage of diethanolamine, hydroxyl silicone, maleic anhydride and sodium bisulfte on the emulsion stability and fatliquoring properties were explored; the reaction temperature and time were also studied. The FT-IR spectra analyses showed that the organosilicone chain segment was incorporated into the fatliquor molecule. The route of synthesis and the best conditions of preparing organosilicone modified palm oil fatliquor were determined. The result of applied experiments showed that this new type of fatliquor had excellent emulsion and dispersion characteristics, and the resultant leather was flexible and full. Note de contenu : - EXPERIMENTAL : Methods and procedures (Materials - Preparation of silicone modified fatliquor - Fourier Transform Infrared spectra - Fatliquoring processes) - RESULTS AND DISCUSSION : Anidation reaction of palm oil with diethanolamine - graft organosilicone onto amidation resultant - Estherificication with maleic anhydride - Preparation of sodium sulphonated ester - Application test of fatliquoring En ligne : https://drive.google.com/file/d/1b225w9zTrUSo2VMRuCd0UVSNMrmulmJp/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11590 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
012969	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Evaluation of antimicrobial activity of Lawsonia Inermis (Henna) against microbial strains isolated from goat skin/leather / A. E. Musa in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVI, N° 5 (05/2011)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVI, N° 5 (05/2011) . - p. 170-175 Titre : Evaluation of antimicrobial activity of Lawsonia Inermis (Henna) against microbial strains isolated from goat skin/leather Type de document : texte imprimé Auteurs : A. E. Musa, Auteur ; A. Tamil Selvi, Auteur ; Rathinam Aravindhan, Auteur ; Balaraman Madhan, Auteur ; Aafreen Fathima, Auteur ; Jonnalagadda Raghava Rao, Auteur Année de publication : 2011 Article en page(s) : p. 170-175 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Antimicrobiens Cuirs et peaux -- Conservation Cuirs et peaux de chèvres Henné Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : In the present work, antimicrobial activity of the aqueous extract from leaves of Lawsonia inermis (henna) has been evaluated. Two gram positive and five gram negative bacterial strains isolated from raw goat skins and three fungal species isolated from finished leathers have been utilized for the antimicrobial studies using aqueous extract from henna leaves. Gram-positive bacteria have found to be completely inhibited by henna at concentrations of 650 ppm and gram negative bacteria have been inhibited by henna concentration between 780 to 910 ppm. Growths of all fungal strains isolated have been inhibited by henna extract at a concentration of 1300 ppm. This study clearly demonstrates that henna offers good antimicrobial activity against the bacterial and fungal species. Note de contenu : - MATERIALS AND METHODS : Materials - Preparation of henna extract - Isolation and screening of bacterial strain from goat skin - Bacterial growth in the presence of henna - Isolation and screening of fungal spores - Preparation of spore suspension - Fungal growth in the presence of henna. - RESULTS AND DISCUSSION : Characterization of bacterial isolated from goat skins - Anti-bacterial activity of henna against bacterial species isolated from goat skins - Characterization of fungal species isolated from finished leather - Anti-fungal activity of henna against fungal strains isolated from leather - Effectiveness of henna as an anti-microbial agent. En ligne : https://drive.google.com/file/d/12eMBNHVROCM-K3obroF6CPEhTeG6-uCI/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11591 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
012969	-	Périodique	Bibliothèque principale	Documentaires	Disponible