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Ajouter le résultat dans votre panierNovel retanning agents for chrome tanned leather based on emulsion - Nano particles of styrene/butyl acrylate co-polymers / E. H. A. Nashy in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVI, N° 9 (09/2011)
Titre : Novel retanning agents for chrome tanned leather based on emulsion - Nano particles of styrene/butyl acrylate co-polymers Type de document : texte imprimé Auteurs : E. H. A. Nashy, Auteur ; A. I. Hussein, Auteur ; M. M. Essa, Auteur Année de publication : 2011 Article en page(s) : p. 241-248 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Copolymère styrène acrylate de butyle
Copolymères en émulsion
Cuirs et peaux
Microscopie électronique à balayage
Microscopie électronique en transmission
Nanoparticules
Retannage
ThermogravimétrieIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : The retanning process is a very important step in the leather manufacturing because it overcomes some of the disadvantages of chrome tannage. For this purpose, two different nano-emulsions of styrene/acylate copolymers were prepared using seed emulsion polymerization technique. The main difference and characteristics of the two copolymer emulsions were studied. In addition, the morphology and the nano-particle size of the copolymer emulsions was proved by transmission electron microscope (TEM). The influence of the prepared copolymer emulsions as retanning agents for chrome tanned leather was also studied. The physico-mechanical properties of the retanned leather, namely, tensile strength, elongation at break and tear strength, were measured. Thermal stability and texture of grain surface and fibers of chrome tanned leather were ewamined using thermal gravimetric analysis (TGA) and scanning electron microscope (SEM), respectively. All these parameters were the main target of this work and used to evaluate the applicability of the copolymers as efficient retanning agents. The results showed an improvement in the physico-mechanical properties, softness, and firmness of grain as well enhancement in thermal stability upon retanning by the prepared copolymer emulsions. Note de contenu : MATERIALS AND TECHNIQUES : Raw materials - Pre-emulsion - Seeded emulsion polymerization - Leather samples preparation - a-Neutralization process - b- Retanning process - c- Dying process - Tranmission electron microscope (TEM) examination - Mechanical properties - Stitch tear (single hole) - Color measurements - Thermal analysis - Scanning electron microscope (SEM) examination
- RESULTS AND DISCUSSION : Characterization of the prepared copolymer latexes - Mechanical properties - Colour measurements - Thermal stability study (TGA) - Scanning electron microscope (SEM)En ligne : https://drive.google.com/file/d/1OGqVJqLPbUolrofwx9alMc0W8sn67_xk/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11885
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVI, N° 9 (09/2011) . - p. 241-248[article]Réservation
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Titre : Studies on phosphonium based combination tanning : less chrome approach Type de document : texte imprimé Auteurs : N. N. Fathima, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Balachandran Unni Nair, Auteur Année de publication : 2011 Article en page(s) : p. 249-256 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Sulfate de tétrakis hydroxyméthyl phosphonium Le sulfate de tétrakis hydroxyméthyl phosphonium est un myxobactéricide qui offre une prévention efficace contre les biofilms microbiens dans les eaux de traitement, et ce, pour une vaste gamme de micro-organismes formant des biofilms. Le sulfate de tétrakis (hydroxyméthyl) phosphonium agit principalement en augmentant la perméabilité de la membrane externe de l'enveloppe de la cellule microbienne, ce qui entraîne la libération rapide de protéines et d'autres substances cellulaires par les cellules. En outre, le sulfate de tétrakis (hydroxyméthyl) phosphonium inhibe le processus de sulfatoréduction dans les bactéries réductrices de sulfate.
Tannage au chrome
Tannage combinéLe tannage combiné se dit des tannages qui allient deux familles ou genre de tannage pour obtenir un résultat additionnant les qualités complémentaires des tannins mis en œuvre par exemple Chrome-Végétal ou Chrome-Synthétique
Tannage organiqueIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : A new combination tanning system based on tetrakis (hydroxymethyl) phosphonium sulfate (THPS) and chromium as a chrome saver approach has been developed. The shrinkage temperature of the leathers obtained was 110°C. The tanning system is versatile in terms of processing both upper and garment leathers. The physical strength characteristics and organoleptic properties of the leathers obtained are comparable to that of chrome tanned leather. Environmental impact assessment shows that there is significant reduction in effluent (TS and sulfate) load when compared to conventional chrome tanning. The molecular level studies show that high level of enzymatic stability is imparted to collagen stabilized using Cr-THPS combination tanning. Mechanistic insights into the stability of collagen against collagenase have been addressed by studying the conformational changes occuring in collagen and collagenase as a result of interaction with Cr-THPS using circular dichroism (CD). The triple helical conformation of collagen is not altered due to interaction with Cr-THPS. Changes in the conformation of collagenase have been observed; which indicates that Cr-THPS stabilizes collagen by altering the conformation of the enzyme. Note de contenu : EXPERIMENTAL METHODS :
- Materials
- Determination of shrinkage temperature
- Chromium-THPS combination tanning
- Post tanning process
- Physical testing of leathers
- Objective assessment of softness through compressibility measurements
- Colour measurement
- Scanning electronic microscopic analysis
- Isolation and characterization of type I collagen
- Circular dichroic (CD) measurements
RESULTS AND DISCUSSION
- Chrome-THPS combination tanning : optimization of BCS with 1.5 % THPS
- Physical strength characteristics of Cr-THPS tanned leathers
- Colour measurements
- Softness measurements
- Scanning electron microscopic studies and hand evaluation of chrome-THPS tanned leathers
- Environmental impact of chrome-THPS combination tanning system
- Studies on molecular level understanding of Cr-THPS-collagen interaction : 1. Enzymatic stability of Cr-THPS tanned collagen - 2. Conformational stability of Cr-THPS tanned collagenEn ligne : https://drive.google.com/file/d/1r2gI6IqYy9sNvHm2zJ_vNFwNyNX4Om5n/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11886
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CVI, N° 9 (09/2011) . - p. 249-256[article]Réservation
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Titre : Non-ammonia deliming using sodium hexametaphosphate and boric acid Type de document : texte imprimé Auteurs : Yunhang Zeng, Auteur ; Jiahong Lu, Auteur ; Xuepin Liao, Auteur ; Qiang He, Auteur ; Bi Shi, Auteur Année de publication : 2011 Article en page(s) : p. 257-263 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Borique, Acide
Cuirs et peaux -- Analyse
DéchaulageOpération consistant à débarrasser les peaux de la chaux et des substances alcalines qui leur ont été appliquées au pelanage.
Eaux usées -- Analyse
Hexamétaphosphate de sodium
Sels d'ammoniumIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : The use of ammonium salt in the deliming process is the primary reason for high ammonia nitrogen content in tannery wastewater. To reduce ammonia nitrogen pollution, a composite of sodium hexametaphosphate (SHMP) and boric acid (BA) was employed for non-ammonia deliming. The synergistic effect of SHMP and BA on deliming of limed cattle hide was investigated by analyzing the pH of deliming liquor, the extent of removal of calcium in pelt and the concentration of total nitrogen (TN) in the effluent. The experimental results indicated that the lowest pH of float during SHMP and BA deliming process was 7.08 and the concentration of hydroxyproline in the deliming liquor was lower than that of ammonia sulfate deliming, which suggest that deliming by SHMP and BA can reduce the damage of pelts. The extent of calcium removal from pelts delimed by using 3 % SHMP and 1 % BA was comparable to that of the pelts delimed with 3.5 % ammonium sulfate. FESEM images and EDS analysis indicated that the deliming by SHMP and BA produced clearer grain with less calcium salts. Compared with ammonium sulfate deliming, TN concentration in SHMP and BA deliming float was reduced by 85 %. Note de contenu : EXPERIMENTAL METHODS : Materials - Deliming processes - Analyses of effluents and pelts - Estimation methods : Determination of Hyp concentration - Determination of TN and TOC concentrations - Determination of calcium content and extent of calcium removal
RESULTS AND DISCUSSION : pH of deliming liquors - Extent of calcium removal from pelts - TN and TOC in deliming effluentsEn ligne : https://drive.google.com/file/d/1ZobH-Rc22M3p5Es6l9D_Tz1bQE6X-VMq/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11887
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Titre : Determination of the tanning degree of vegetable-tanned leather by infrared spectroscopy (FTIR) Type de document : texte imprimé Année de publication : 2011 Article en page(s) : p. 264-271 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Chimiométrie
Fourier, Spectroscopie infrarouge à transformée de
Mimosa et constituants
QuebrachoLe quebracho est un arbre à écorce ligneuse, mesurant 30 mètres de haut, à feuilles tannées et à fleurs tubulées blanches.
Quebracho est l'un des noms communs, en espagnol, d'au moins trois espèces similaires d'arbres originaires du Gran Chaco, en Amérique latine : Schinopsis lorentzii (quebracho colorado santiagueño), de la famille des Anacardiaceae ; Schinopsis balansae (quebracho colorado chaqueño), de la même famille ;
Aspidosperma quebracho-blanco (quebracho blanc), de la famille des Apocynaceae.
Ces trois espèces sont riches en tanin et fournissent un bois très dur, particulièrement résistant. Leur nom provient de l'espagnol quiebrahacha, qui signifie brise-hache.
Réflexion totale atténuée
Tannage végétal -- AnalyseIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : We have developed an analytical method to determine the tanning degree (TD) and the parameters associated with its calculation by means of the instrumental technique of Fourier Transform mid-infrared spectroscopy (FTIR) with attenuated total reflection mode module (ATR) and chemometric treatment of spectral data. Early studies show that it is possible to make the determination of several parameters simultaneously (TD, combined tannins, hide substance and leather substance) using FTIR spectra recorded directly on the leather tanned with a mixture of mimosa and quebracho, thus reducing dramatically the time of analysis and avoiding the use of pollutants. Note de contenu : THEORETICAL FRAMEWORK : Mid-infrared spectroscopy by Fourier Transform (FTIR) - Chemometrics
EXPERIMENTAL : Samples - Instrumental and software - Reference methods - Obtaining spectra - Calculation of resultsEn ligne : https://drive.google.com/file/d/1Tz0m4rmjbk2wim5D_3fL4eqah0SiVUMn/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=11888
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| Code-barres | Cote | Support | Localisation | Section | Disponibilité |
|---|---|---|---|---|---|
| 13284 | - | Périodique | Bibliothèque principale | Documentaires | Disponible |
