| Titre : |
Theory and mechanism of tanning present thinking and future implications for industry |
| Type de document : |
texte imprimé |
| Auteurs : |
Anthony D. Covington, Auteur |
| Année de publication : |
2001 |
| Article en page(s) : |
p. 24-34 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Entropie (thermodynamique)
Hydrogène
Hydroxyproline
Tannage au chrome
Tannage organique
Température de retrait
|
| Index. décimale : |
675.2 Préparation du cuir naturel. Tannage |
| Résumé : |
The range and nature of reactions that contribute to the stability of collagen are discussed in terms of the definition of tanning. Previous ideas of the origin of hydrothermal stability of modified collagen are included in the discussion. A new theory of the origin of hydrothermal stability is defined, based upon the relative contributions of entropic and enthalpic changes to collagen by interactive chemical processes. These changes culminate in stabilisation by the formation of matrices, that are capable of producing high hydrothermal stability. Ts> 100°C. The theory explains the whole range of observed effects in mineral (inorganic) and organic tanning reactions, thereby creating an inclusive, unifying model of collagen stabilisation. Furthermore, it allows not only prediction of the effects of any new tanning processes, mineral or organic, together with modifications to current processes, but also specifies where new chemistries might be sought, to achieve high hydrothermal stability. |
| Note de contenu : |
- The definition of tanning
- The shrinking transition
- The roles of hydroxyproline and hydrogen
- Entropic effect
- The thermodynamics of tanning and shrinking
- The shrinking reaction
- Organic tanning
- Chromium(III) tanning
- Completing the theory of tanning
- Future developments
- Table 1 : The rise in shrinkage temperature caused by traditional tannages
- Table 2 : Typical shrinkage temperatures for leathers tanned with modern chemistries
- Table 3 : The dependence of shrinkage temperature on imino acid content of collagens
- Table 4 : The effect of polypeptide structure on the unfolding transition temperature
- Table 5 : The effects of sodium salts on collagen
- Table 6 : The effect of fluoride ion on collagen stabilisation
- Table 7 : Activation parameters at 333 K for different tannages (adapted from ref. 26)
- Table 8 : The relationship between shrinkage temperature and the parameters of the shrinking reaction
- Table 9 : The size of the cooperating unit in unmodified and modified collagen
- Table 10 : The maximum effect of excess carboxylate on the shrinkage temperature of leather tanned with 40 % basic chromium(lhl) perchhorate
- Table 11 : Apparent shrinkage temperature of hide powder equilibrated with alcohol
|
| En ligne : |
https://drive.google.com/file/d/1VSARpzkIMKqpj_JryvcFwaZ5TJft8nZ5/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40591 |
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 85, N° 1 (01-02/2001) . - p. 24-34
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Theory and mechanism of tanning present thinking and future implications for industry in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 85, N° 1 (01-02/2001)
