Alternative tanning agent for leather industry from a sustainable source : Dialdehyde starch by periodate oxidation / Cigdem Kilicarislan Ozkan in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVI, N° 3 (03/2021)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVI, N° 3 (03/2021) . - p. 89-99 Titre : Alternative tanning agent for leather industry from a sustainable source : Dialdehyde starch by periodate oxidation Type de document : texte imprimé Auteurs : Cigdem Kilicarislan Ozkan, Auteur ; Hasan Ozgunay, Auteur Année de publication : 2021 Article en page(s) : p. 89-99 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Agents de tannage Amidon dialdéhyde Amidons -- Oxydation Caractérisation Cuirs et peaux -- Propriétés organoleptiques Cuirs et peaux -- Propriétés physiques Poids moléculaires Tannage Tannage -- Aspect de l'environnement Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Dialdehyde starches with different aldehyde content from native corn starch were prepared by sodium periodate oxidation to be used as a tanning agent in leather making. For this purpose, native corn starch was oxidized with sodium metaperiodate in different molar ratios. After oxidation processes, the yields, solubility in water and aldehyde contents of the obtained dialdehyde starches were determined as well as structure characterizations by Proton Nuclear Magnetic Resonance Spectroscopy, Fourier Transform Infrared Spectroscopy and Gel Permeation Chromatography. Evaluating the gel permeation chromatography data, the dialdehyde starch samples which were thought to be in appropriate molecular weight/size to penetrate into skin fibers were selected to be used in the tanning process. Their tanning abilities were evaluated by investigating hydrothermal stabilities, filling and fiber isolation characteristics and physical properties determined by mechanical tests and organoleptically. From the evaluation of the results, it was revealed that sodium metaperiodate oxidized starches which have appropriate molecular weight and adequate aldehyde content has a remarkable tanning effect and can be utilized as a tanning agent with the advantages of not necessitating pickling process which means saving time and simplifying the production but more importantly offering an important advantage from an environmental point of view. Note de contenu : - Characterizations - Tanning properties of dialdehyde starch samples - Table 1 : Tanning recipe for the pelt pieces - Table 2 : Molecular weight distribution of native and oxidized starches - Table 3 : Tanning properties of oxidized starches - Table 4 : Physical properties of tanned leathers with oxidized starches - Table 5 : Organoleptical properties of tanned leathers with oxidized starches DOI : https://doi.org/10.34314/jalca.v116i3.4249 En ligne : https://drive.google.com/file/d/1Ao7z1sapfoabaz0Uek5C2uMsZkBOMAoh/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35436 [article]

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Modelling the solubility of films prepared from collagen hydrolysate / Pavel Mokrejs in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 94, N° 6 (11-12/2010)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 94, N° 6 (11-12/2010) . - p. 231-239 Titre : Modelling the solubility of films prepared from collagen hydrolysate Type de document : texte imprimé Auteurs : Pavel Mokrejs, Auteur ; Dagmar Janacova, Auteur ; Petr Svoboda, Auteur ; Vladimir Vasek, Auteur Année de publication : 2010 Article en page(s) : p. 231-239 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Amidon dialdéhyde Analyse thermique Biodégradation Collagène Couches minces 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. Hydrolysats de protéines Plastifiants Solubilité Thermogravimétrie Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The work deals with modeling the solubility of biodegradable films prepared from collagen hydrolysate. To this purpose, we studied the effect of added plasticizer, cross-linking agent or additional thermal annealing on the dissolution rate of films ; experiments were planned as factorial tests of the 2-3 type. The basis for preparing films was a 15 % (w/v) solution of hydrolysate with various additions of plasticizer - glycerol (GLY) in quantities of 0,5 and 10 % (related to hydrolysate dry matter, w/w), cross-linking agent - dialdehyde starch (DAS) in quantities of 0,4 and 8 % (related to hydrolysate dry matter, w/w). Films were prepared by casting solution on silicone plates with subsequent evaporation of solvent (water) in 72 hours at 35°C. A part of the films was subjected to addition thermal annealing at 62,5 and 90°C. Solubility tests on films were performed in water at 25°C. The percentage of dissolved film was determined through gravimetry. The results of film solubility were assessed statistically and graphic models were produced. It was found that added dialdehyde starch and additional thermal annealing very prominently affect the course of film dissolution. Qualities further studied with prepared films were thermal properties by DSC and TGA techniques. En ligne : https://drive.google.com/file/d/120G7dUuljbC50drzKR-GMmvij-bqkKhh/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=10808 [article]

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A molecular level investigation of dialdehyde starch interaction with collagen for eco-friendly stabilization / Gladstone Christopher Jayakumar in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CX, N° 5 (05/2015)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CX, N° 5 (05/2015) . - p. 145-151 Titre : A molecular level investigation of dialdehyde starch interaction with collagen for eco-friendly stabilization Type de document : texte imprimé Auteurs : Gladstone Christopher Jayakumar, Auteur ; Swarna Vinodh Kanth, Auteur ; Jonnalagadda Raghava Rao, Auteur ; Balachandran Unni Nair, Auteur Année de publication : 2015 Article en page(s) : p. 145-151 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Amidon dialdéhyde Antienzymes Collagène Dynamique moléculaire Réticulation (polymérisation) Stabilisants (chimie) Stabilité thermique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The current study investigates Dialdehyde Starch (DAS) as a stabilizing agent for collagen. DAS is a well established crosslinking agent for protein; however, molecular interaction with collagen was not elucidated. Dialdehyde involves in the formation of inter and intra crosslinking with protein which renders higher stability against heat and enzyme. Crosslinking efficiency of DAS with collagen was found to increase with increase in the concentration. DAS interacted collagen membrane exhibited an increase in the thermal stability of about 35°C at pH 8. Swelling degree of collage-DAS membranes were found to decrease with increase in the concentration of DAS owing to the shift in the nucleation behavior in collagen fibrillogenesis. DAS treated collagen membrane shows 90% resistance to collagenase due to the unavailability of cleaving sites in collagen-DAS fibres. Reconstittued collage-DAS collagen membranes showed increase in cell proliferation which signifies its non-toxic characteristics. Therefore, DAS can be a new class of green tanning agent for skin stabilization and also finds applications in scaffold preparation. Note de contenu : - MATERIALS AND METHODS : Reagents and chemicals - Preparation of type I collagen - Preparation of reconstituted collagen membranes - Crosslinking conditions - Crosslinking efficiency - Swelling ratio - Thermal resistance of DAS stabilized collagen membrane hydrothermal temperature - Calorimetric measurement - Denaturation temperature - Collagenolytic activity of DAS stabilized collagen matrix - Scanning Electron Microscopy studies of DAS stabilized collagen membrane - In vitro cytotoxicity analysis - RESULTS AND DISCUSSION : Effiency of DAS interaction with biomembrane - TNBS assay - Water absorption in collagen-DAS biomembrane - Thermal stability of collagen-Das biomembrane - DAS-collagen biomembrane resistance against collagenase - Morphological study of collagen-DAS biomembrane - Evaluation of cell proliferation on collagen - DAS biomembrane substrate - Plausible mechanism of dialdehyde starch interaction with collagen En ligne : https://drive.google.com/file/d/1Xdg1FiqhE-W-sP_5lxd2otPh_8Tl6HsR/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=24055 [article]

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Saccharides in leather / Karl Flowers in INTERNATIONAL LEATHER MAKER (ILM), N° 54 (07-08/2022)  

[article]  inINTERNATIONAL LEATHER MAKER (ILM) > N° 54 (07-08/2022) . - p. 44-45 Titre : Saccharides in leather Type de document : texte imprimé Auteurs : Karl Flowers, Auteur Année de publication : 2022 Article en page(s) : p. 44-45 Langues : Anglais (eng) Catégories : Amidon dialdéhyde Biomatériaux Carboxyméthylcellulose Carraghénanes Cuirs et peaux -- Finition Glucides Hémicellulose Les principaux polysaccharides non cellulosiques du bois. Le bois est constitué d'hémicellulose (28 à 35%), de cellulose et de lignine. hydrocolloïdes Lignocellulose Polymères Post-tannage Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The November/December 2020 issue of International Leather Maker (page 42) covered the new bio-based materials that are being looked at for the post-tanning and finishing. This article will examine the practical use of the chemistry in today's modern process and will try to explain why these are advantageous. To remind the reader, the materials covered in that editorial article were: - Nano-biocomposites - Cellulose grafts - Regenerated cellulosics - Lignocelluloses - Finishing cellulosics. Since that edition of ILM in 2020, many more polysaccharides have been examined in the use of hydrogel technology, but also a look back in time shows the experience of tanners, the textbooks, leather journals and product sheets shows that saccharides have been used as monosaccharides, disaccharides or polysaccharides for a long time. Substances used include: - Glucose for the manufacture of chromium salts - suppression - Dialdehyde starch - Disaccharides in heavy vegetable manufacture (filling and grain plasticisation). The use of dialdehyde starch was first examined in the leather industry in the 1970s. It was used by a few tanner leathers, but then seemed to fade away as other priorities in the industry started to materialise. The industry was also not prepared for the extensive post-tanning that was needed for these leathers. The perfection of the glutaraldehyde tannage would only corne through mastery of chrome-free, post-tanning that was mainly invented in the late 1990s. Starch structure opening through oxidative ring opening allowed the starch to react, through the Maillard reaction, with the collagen. Large, bulky dialdehyde starch did not always penetrate well and many companies dropped it when they realised that the tannage may result in a raw centre. Oxidation of saccharides that opens the compound has been modified and tweaked numerous times since the 70s. If the density of the starch opening is high the result will be a polymer that can react with the collagen in several places as the compound can bind with amine, hydroxyl and amide groups along the way. If the leather is not retanned and fatliquored correctly, the leather will be stiff and will have an unpleasant break. Note de contenu : - Biocomposites - Hydrogels - Lignocelluloses - Fig. 1 : The dialdehyde starch polymer - Fig. 2 : Carboxymethylcellulose - Fig. 3 : Chemical structure of carrageenan - Fig. ' : The lignin, cellulose and hemicellulose mass in plants En ligne : https://drive.google.com/file/d/1XKQy8bFSD2i3kqaG2C94mfBE2hMHs9b5/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37951 [article]

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