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[article]
Titre : |
Essential chromium ? |
Type de document : |
texte imprimé |
Auteurs : |
Eleanor M. Brown, Auteur ; Maryann M. Taylor, Auteur |
Année de publication : |
2003 |
Article en page(s) : |
p. 408-414 |
Note générale : |
Bibliogr. |
Langues : |
Américain (ame) |
Index. décimale : |
675 Technologie du cuir et de la fourrure |
Résumé : |
During the production of chrome-tanned leather, chromium is incorporated into the leather with at least three types of interactions. Most important is the chromium that is complexed with collagen to give leather its characteristic properties. Other interactions include nonproductive binding of chromium to collagen and adsorption of chromium by the collagen matrix. To evaluate the extent and possible effects of these other interactions, we extracted chrome shavings with water, HCl, or EDTA to remove adsorbed or loosely bound chromium. The effect of chromium removal on hydrothermal stability was followed by differential scanning calorimetry, and the chromium content of extracts was determined by atomic absorption spectrometry. Extraction of less than 2% of the chromium initially present had no effect on the denaturation temperature, but removal of 3% to 10% of the chromium resulted in a 20°C decrease in the denaturation temperature. As 10% to 60% of the chromium was extracted, the denaturation temperature decreased an additional 30°C, nearly reaching the temperature expected for leather that was not tanned. The results suggest that up to 2% of the chromium is simply adsorbed, and most easily removed. The next 3% to 10% is, however, important for the thermal stability of the shavings. Beyond this level, extraction with EDTA continually shifts the chromium-collagen equilibrium and the denaturation temperature to lower values. The final approximately 40% of the chromium appears to be bound to the collagen, but no longer crosslinked. |
En ligne : |
https://drive.google.com/file/d/15VqcpVGPaHzcHsDsf3vEmebpqPLjnN6r/view?usp=drive [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4163 |
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVIII, N° 10 (10/2003) . - p. 408-414
[article]
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