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Auteur Bi Shi
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Sichuan University - Chengdu - China
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The reaction of vegetable tannin-aldehyde-collagen - A further understanding of vegetable tannin-aldehyde combination tannage / Zhongbing Lu in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 87, N° 5 (09-10/2003)
[article]
Titre : The reaction of vegetable tannin-aldehyde-collagen - A further understanding of vegetable tannin-aldehyde combination tannage Type de document : texte imprimé Auteurs : Zhongbing Lu, Auteur ; Xuepin Liao, Auteur ; Bi Shi, Auteur Année de publication : 2003 Article en page(s) : p. 173-178 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Calorimétrie
Cuirs et peaux de moutons
Mimosa et constituants
Oxazolidine
Poudre de peaux
Stabilité hydrothermale
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 organique
Tannage végétal
Température de retraitIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Using mimosa as a vegetable tanning agent and oxazolidine as an aldehydic tanning agent, the approaches of hydrothermal analysis, hydrogen bond and hydrophobic bond breaking as well as chemical modifications of collagen were employed to investigate the effects of hydrogen bonds, hydrophobic bonds and side amino groups of collagen on vegetable tanning, aldehyde tanning and vegetable-aldehyde combination tanning The results indicated that the aldehyde should still predominantly react with the side amino group of collagen even when added after vegetable tanning. However, the aldehyde could further react with the vegetable tannin and thus form a cross-linkage between collagen and the vegetable tannin if high-activity nucleophilic sites are present in the tannin molecules. As a result, the synergistic effect of the combination tanning on increasing the hydrothermal stability of collagen fibres was achieved and the combined stability of vegetable tannin and collagen was strengthened remarkably. This mechanism is appropriate for describing combination tanning with condensed tannins which contain nucleophilic sites. However, with hydrolysable tannins, no aldehydic cross-linkage between collagen and tannin could be observed.
In general, this research revealed that vegetable-aldehyde combination tanning has features which are different from those previously assumed. According to the mechanism suggested in this paper, all the phenomena relating to vegetable tannin -aldehyde-collagen interactions can be well understood.Note de contenu : - EXPERIMENTAL METHODS :
- Materials
- Methods
- Vegetable tanning of hide powder
- Combination tanning of hide powder
- Aldehyde tanning of hide powder
- Hydrogen bond breaking
- Hydrophobic bond breaking
- Differential scanning calorimetry (DSC) studies
- Amino analysis
- RESULTS AND DISCUSSION
- Table 1 : The influence of urea solution on hydrothermal stability of collagen (oC)
- Table 2 : The influence of n-propanol solution on hydrothermal stability of collagen (oC)
- Table 3 : The content of typical amino acids in the hide powders before and after chemical modifications (number of amino acid / 1000 amino acids)
- Table 4 : Ts and Tp of hide powders tanned by different tannages (oC)
- Table 5 : The shrinkage temperature (Ts) of the sheepskin leathers tanned by combination tannage using 20% tannin extract and 4% oxazolidine
- Table 6 : The influence of sequence in combination tannage on shrinkage temperatureEn ligne : https://drive.google.com/file/d/1hO3CzXXRcP8Uf_g31Ja9PijSfHmCzAJ-/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39707
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 87, N° 5 (09-10/2003) . - p. 173-178[article]The reinforcement of leather split by constructing an interpenetrating network via in-situ recombination of PVA / Xu Weixing in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 8 (08/2018)
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Titre : The reinforcement of leather split by constructing an interpenetrating network via in-situ recombination of PVA Type de document : texte imprimé Auteurs : Xu Weixing, Auteur ; Hui Zeng, Auteur ; Jianfei Zhou, Auteur ; Ya-Nan Wang, Auteur ; Bi Shi, Auteur Année de publication : 2018 Article en page(s) : p. 255-263 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Composites
Composites -- Propriétés mécaniques
Composites -- Propriétés thermiques
Cuirs et peaux
Matériaux -- Renforcement
Polyacétate de vinyle
Polymères -- Propriétés mécaniques
Potentiométrie
Réseaux polymèresIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : In order to improve the quality and utilization of leather split, the strength of leather split should be enhanced. The in-situ polymerization of some monomers has proven to be an effective approach in constructing an interpenetrating network (IPN) in split and increasing its strength. But this method is almost unacceptable in practice because of the use of volatile monomers and organic solvents. In this study, a new method to construct the IPN structure in split, in-situ recombination, was developed. Polyvinyl alcohol (PVA) was used as compositing agent, and its molecular structure and modification conditions were optimized. Scanning electron microscope (SEM), potentiometric analyzer and differential scanning calorimeter (DSC) were used to characterize the mechanism of in-situ recombination. The results suggested that PVA with an average polymerization degree of 500 and an average alcoholysis degree of 88% could enhance the strength of split most effectively through compositing reaction of PVA and split in 5% PVA aqueous solution for 120 min under 80°C and pH 7.0. The IPN structure was successfully constructed between PVA and collagen fibers via in-situ recombination. A method to enhance the strengths of leather split with practical application was established. Note de contenu : - EXPERIMENTAL : Materials and equipment - Preparation of PVA/split composites - Measurements and instruments
- RESULTS AND DISCUSSION : Effect of compositing time on mechanical properties of PVA/split composites - Effect of polymerization degree and alcoholysis degree of PVA on mechanical properties of PVA/split composites - Effect of PVA concentration on mechanical properties of PVA/split composites - Morphology analysis of PVA/split composite - Potentiometric analysis of PVA/split composite - Thermal behavior of PVA/split compositeEn ligne : https://drive.google.com/file/d/1k-il4rNBlYeS-mLyrSM8DIC2KCqz1VkM/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30842
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIII, N° 8 (08/2018) . - p. 255-263[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 20115 - Périodique Bibliothèque principale Documentaires Disponible The water vapour permeability of leather finished by thermally responsive polyurethane / Haojun Fan in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 89, N° 3 (05-06/2005)
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Titre : The water vapour permeability of leather finished by thermally responsive polyurethane Type de document : texte imprimé Auteurs : Haojun Fan, Auteur ; Ling Li, Auteur ; Xinnian Fan, Auteur ; Bi Shi, Auteur Année de publication : 2005 Article en page(s) : p. 121-125 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Analyse thermomécanique dynamique
Butanediol
Caractérisation
Cuirs et peaux -- Finition
Diisocyanate d'isophorone
Gonflement (physique)
Matériaux thermosensibles
Mesure
Perméabilité
Poly-e-caprolactone
Polymères en émulsion
Polyuréthanes
Propionique diméthylol, Acide
Revêtements organiques
Transition de phaseEn physique, une transition de phase est une transformation du système étudié provoquée par la variation d'un paramètre extérieur particulier (température, champ magnétique...).
Cette transition a lieu lorsque le paramètre atteint une valeur seuil (plancher ou plafond selon le sens de variation). La transformation est un changement des propriétés du système.
Vapeur d'eauIndex. décimale : 675 Technologie du cuir et de la fourrure Résumé : A water-based thermally-responsive polyurethane (TRPU), based on the crystalline soft segment from the reaction of polycaprolactone diol (PCL) with isophorone diisocyanate (IPDI) and the crystalline hard segment from the reaction of IPDI -1,4-butanediol (BDO) together with dimethylolpropionic acid (DMPA), was synthesized and used in water vapour permeable leather finishing.
Differential Scanning Calorimetry (DSC), Dynamic Mechanical Thermal Analyzer (DMTA), water swelling and water vapour permeability (WVP) were measured to evaluate how the structure of PU and the temperature influence the WVP of PU films and finished leathers.
In contrast to common polyurethane elastomer (PUE) with an amorphous reversible phase, the TRPU with a crystalline reversible phase shows a phase-separated structure and a phased transition temperature (Ttrans) at normal use temperature. The water swelling and water vapour permeability of both TRPU film and finished leather are found to depend on the inner structure of the polymers and the temperature. When the temperature exceeds the Ttrans, a significant increase of WVP from 4100g/m2/day to 10500g/m2/day was observed for finished leather in spite of some decrease of WVP compared with un-finished leather. Leather finished with common PUE appears to have a low WVP and only a slightly increased value over the temperature range.Note de contenu : - EXPERIMENTAL PROCEDURE : Material, preparation of polyurethane and testing - Film casting and leather specimen preparation - Differential Scanning Calorimetry (DSC) and
Dynamic Mechanical Thermal Analyzer (DMTA) - Water swelling of PU films - Measurement of water transport properties
- RESULTS AND DISCUSSION : Phase transition temperature of polyurethanes - Water swelling of PU films - Water vapour permeability
- Table 1 : Characteristics of the TRPU and PUE prepared
- Table 2 : Storage modulus of PU samples as a function of temperature
- Table 3 : Comparison of water swelling of different PU filmsEn ligne : https://drive.google.com/file/d/1qQXbjgGgLXlKIkAE_ZSG7m0uac1UdoeO/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39272
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 89, N° 3 (05-06/2005) . - p. 121-125[article]Theoretical elucidation of the structure-activity relationship for tannins used to scavenge radicals / Wenhua Zhang in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 89, N° 4 (07-08/2005)
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Titre : Theoretical elucidation of the structure-activity relationship for tannins used to scavenge radicals Type de document : texte imprimé Auteurs : Wenhua Zhang, Auteur ; Bi Shi, Auteur Année de publication : 2005 Article en page(s) : p. 137-140 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Chimie numérique La chimie numérique ou chimie informatique, parfois aussi chimie computationnelle, est une branche de la chimie et/ou de la physico-chimie qui utilise les lois de la chimie théorique exploitées dans des programmes informatiques spécifiques afin de calculer structures et propriétés d'objets chimiques tels que les molécules, les solides, les agrégats atomiques (ou clusters), les surfaces, etc., en appliquant autant que possible ces programmes à des problèmes chimiques réels. La frontière entre la simulation effectuée et système réel est définie par le niveau de précision requis et/ou la complexité des systèmes étudiés et les théories employées lors de la modélisation. Les propriétés recherchées peuvent être la structure (géométrie, relations entre constituants), l'énergie totale, l'énergie d'interaction, les charges, dipôles et moments multipolaires, fréquences vibrationnelles, réactivité ou autres quantités spectroscopiques, sections efficaces pour les collisions, etc. Le domaine le plus représenté de la discipline est le traitement des configurations électroniques des systèmes.
L'expression chimie numérique est parfois également utilisée pour désigner tous les champs scientifiques qui recouvrent à la fois la chimie et l'informatique.
Chrome hexavalent
Pièges chimiquesSubstance chimique qui inactive, de façon temporaire ou définitive, ou élimine une entité moléculaire par une réaction chimique.
Un piège chimique est souvent utilisé pour piéger des intermédiaires réactionnels, tels des radicaux, afin de modifier le déroulement d’une réaction.
Radicaux libres (chimie)
Relations structure-activité
TaninsIndex. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Tannin extracts have been used to scavenge free radicals and prevent chromium VI formation in leathers tanned with chrome salts, but their structure-activity relationship has not been clarified theoretically. In this paper, model tannin compounds representing condensed tannins and hydrolysable tannins were evaluated using the approach of computational chemistry. By using the B3LYP/6-31G(d) method, two kinds of theoretical parameters, i.e. OH bond dissociation energy (BDE) and adiabatic ionization potential (IP), were obtained to characterize H-atom transfer and concerted proton electron transfer mechanisms respectively in the free radical scavenging process.
Both BDE and IP, gave the order of free radical scavenging activity : EGCG>ECG>EGC>EC, and digallic acid >ellagic acid. Furthermore, all the calculation results from electron transfer mechanism and H-abstraction mechanism indicated that the condensed tannins that contain galloyl groups seem to possess the highest free radical scavenging activity.Note de contenu : - Table : BDEO-Hs and IPs of model compounds of tannins calculated using the B3LYP/6-31G(d) method En ligne : https://drive.google.com/file/d/1zECf_2n74I7LyvkHaCZH-bfQpalIcjol/view?usp=share [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=39243
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 89, N° 4 (07-08/2005) . - p. 137-140[article]A theoretical study on autoxidation of unsaturated fatty acids and antioxidant activity of phenolic compounds / Wenhua Zhang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CII, N° 3 (03/2007)
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Titre : A theoretical study on autoxidation of unsaturated fatty acids and antioxidant activity of phenolic compounds Type de document : texte imprimé Auteurs : Wenhua Zhang, Auteur ; Bi Shi, Auteur ; Jeff Shi, Auteur Année de publication : 2007 Article en page(s) : p. 99-105 Note générale : Bibliogr. Langues : Américain (ame) Résumé : The purpose of this research is to assess oxidative stability of unsaturated fatty acids and their derivatives in leather fatliquors, and to predict effective antioxidants suitable to be used for the systems. The B3LYP/6-31G(d,p) method was employed to obtain C-H and O-H bond dissociation energies of unsaturated fatty acids and phenolic compounds. Using palmitoleic, oleic, ricinoleic, erucic, linoleic, linolenic, and a-eleostearic as models, the autoxidation of unsaturated fatty acids was theoretically clarified based on free-radical chain reaction mechanism and structure-oxidative stability relationships. Calculated results showed that the allylic hydrogens of unsaturated fatty acids are easily abstracted. Unsaturated fatty acid stability is dependent on the number of double bonds and the existence of the substituent group in the carbon chain. Unsaturated fatty acids that contain more double bonds, particularly conjugated double bonds, would be easier to oxidize. Theoretical calculations suggest that the esters are more stable than the free fatty acids. The electron-donating substituent group also favors oxidative stability of unsaturated fatty acids. However, the carbon chain length doesn’t significantly affect autoxidation of unsaturated fatty acids. The antioxidative activity of phenolic compounds in unsaturated fatty acids was also studied. Calculated results showed that gallic acid, epigallocatechin, tocopherol and caffeic acid are effective antioxidants in unsaturated fatty acid systems. Epicatechin, ellagic acid and ferulic acid might be suitable to be used as antioxidants for unsaturated fatty acids containing one double bond. En ligne : https://drive.google.com/file/d/1mZJZvUcEvsIjmIklB1hQub2igT0UnsI3/view?usp=drive [...] Format de la ressource électronique : Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3366
in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CII, N° 3 (03/2007) . - p. 99-105[article]Réservation
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Code-barres Cote Support Localisation Section Disponibilité 007160 - Périodique Bibliothèque principale Documentaires Disponible Thermodynamic investigations on chrome and aluminum tanning / Li Wang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 11 (11/2017)
PermalinkTransposition of chrome tanning in leather making / Chao Wu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 6 (06/2014)
PermalinkTwo-stage temperature change chrome tanning : A more sustainable tanning process / Hui Zeng in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIV, N° 5 (05/2019)
PermalinkUltrasonic removal of organic pollutants in tannery wastewater / Bi Shi in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVII, N° 3 (03/2002)
PermalinkUtilization of tannery solid waste : Dry strength additive for papermaking / Yaohui You in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVIII, N° 7 (07/2013)
PermalinkVisualization and quantification of penetration/mass transfer of acrylic resin retanning agent in leather using fluorescent tracing technique / Yunhang Zeng in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXI, N° 11 (11/2016)
PermalinkVisualization of penetration and reaction of aldehyde tanning agent in leather using fluorescence technique / Ying Song in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXV, N° 7 (07/2020)
PermalinkWaterborne polyurethane/O-MMT nanocomposites for flame retardant leather finishing / Zhang Xiuli in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 94, N° 2 (03-04/2010)
PermalinkWearable synthetic leather-based high-performance X-ray shielding materials enabled by the plant polyphenol- and hierarchical structure-facilitated dispersion / Linping Yan in COLLAGEN AND LEATHER, Vol. 5 (2023)
PermalinkWet-white based on an amphoteric polymer / Bi Shi in LEATHER INTERNATIONAL, Vol. 215, N° 4829 (04/2013)
PermalinkWet-white leather processing : a new complex combination tannage / Luo Jianxun in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 95, N° 3 (05-06/2011)
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