High stability organic tanning using plant polyphenols. Part 2 / Bi Shi in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 83, N° 1 (01-02/1999)

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 83, N° 1 (01-02/1999) . - p. 8-13 Titre : High stability organic tanning using plant polyphenols. Part 2 : The mechanism of the vegetable tannin-oxazolidine tannage Type de document : texte imprimé Auteurs : Bi Shi, Auteur ; Youjie He, Auteur ; Haojun Fan, Auteur ; Shaoyu Zeng, Auteur ; Anthony D. Covington, Auteur ; Geoffrey E. Attenburrow, Auteur Année de publication : 1999 Article en page(s) : p. 8-13 Note générale : Bibliogr. Langues : Anglais (eng) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Catechin was used as a model for condensed vegetable tanning, to elucidate the reaction between the flavonoid ring system and oxazolidines in the combination tannage. Using 1H-NMR, 13C-NMR and paper chromatography, it is shown that the crosslinking reaction occurs predominantly at the C-6 and C-8 of the phloroglucinol A ring of catechin. The crosslinker reacts at the C-5 of oxazolidine, by ring opening and reacting via the N-methylol intermediate. Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=7851 [article]

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Oxidising degradation of Valonia extract and utilisation of the products. Part 1. Oxidising degradation of Valonia extract and characterisation of the products / Bi Shi in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 84, N° 6 (11-12/2000)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 84, N° 6 (11-12/2000) . - p. 258-262 Titre : Oxidising degradation of Valonia extract and utilisation of the products. Part 1. Oxidising degradation of Valonia extract and characterisation of the products Type de document : texte imprimé Auteurs : Bi Shi, Auteur ; Ying Di, Auteur ; Youjie He, Auteur ; Lijiang Song, Auteur ; Yu Zhao, Auteur Année de publication : 2000 Article en page(s) : p. 258-262 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Aluminium trivalent Chrome trivalent Complexation (chimie) Couleur Extraits de plantes Oxydation Peroxyde d'hydrogène Le peroxyde d'hydrogène (H2O2), communément appelé eau oxygénée ou encore perhydrol (appellation industrielle), est un composé chimique liquide et visqueux, aux puissantes propriétés oxydantes (il est aussi réducteur). C'est donc un agent blanchissant efficace qui sert de désinfectant et (à haute concentration) d'oxydant ou monergol dans les fusées spatiales. Poids moléculaires Résistance chimique Tanins végétaux Valonia et constituants Valonia est un genre d'algues vertes de la famille des Valoniaceae. La taille d'une seule cellule pluri-nucléée peut atteindre 2 cm chez certaines espèces. (Wikipedia) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Oxidation using H2O2 brings about degradation of valonia extract. Three typical products with novel properties were obtained when 20%, 40% and 60% H2O2 (conc. 50%) were used. Determinations indicated that the oxidising reaction leads to lowering of molecular weight, lightening of colour, improving of acid and salting-out resistances and increasing of hydrophilic groups, carboxyl in particular. The more interesting results are that penetrating rates of the degraded products in pelt are markedly accelerated and that the alkali resistance of complex compounds of the products and Cr(III) or Al(III) is considerably increased. The effects above are enhanced with increasing offer of H20.The conditions for oxidising degradation are described and the potentials of utilising the products are discussed. Note de contenu : - EXPERIMENTAL PROCEDURES : Oxidising degradation of valonia extract - Determination of molecular weight distribution - Colour determination - Characterisation of structure - Acid resistance and salting-out effect determinations - Determination of tanning property - Complexing characteristics with Al(III) and Cr (III) - RESULTS AND DISCUSSION - Table 1 : Molecular weight distributions of oxidised degradation products of valonia extracts - Table 2 : The colour of valonia extract and its oxidised degradation products - Table 3 : Precipitate ratios (%) of valonia extract and its oxidised degradation products at different pH* - Table 4 : Precipitate ratios (%) of valonia extract and its oxidised degradation products in NaC1 solution - Table 5 : The tanning properties of valonia extract and its oxidised degradation products* - Table 6 : Precipitating pH of complex solutions of oxidised degradation products and Cr(III) - Table 7 : Precipitating pH of complex solutions of oxidised degradation products and Al(III) En ligne : https://drive.google.com/file/d/1MNgqR-q-yGLMFjML87uHVZ7aRinbwt3x/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=40815 [article]

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Synthesis, characterisation and application of novel valonia tannin based waterborne polyurethane with natural colour / Yang Liu in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 103, N° 3 (05-06/2019)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 103, N° 3 (05-06/2019) . - p. 135-141 Titre : Synthesis, characterisation and application of novel valonia tannin based waterborne polyurethane with natural colour Type de document : texte imprimé Auteurs : Yang Liu, Auteur ; Haihang Luo, Auteur ; Benyapathitiwong Ruj, Auteur ; Tao You, Auteur ; Youjie He, Auteur Année de publication : 2019 Article en page(s) : p. 135-141 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Algues marines Caractérisation Cuirs et peaux -- Finition Essais dynamiques Humidité -- Absorption:Eau -- Absorption Pliage (mécanique) Polymères -- Analyse Polymères -- Synthèse Polymères en émulsion Polyuréthanes Résistance chimique Solidité de la couleur Taille des particules Tanins végétaux Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : A novel natural coloured waterborne polyurethane (PU) based on valonia tannin was successfully synthesised and characterised. A structural study of the polymer by Fourier Transform Infra Red (FTIR) spectroscopy confirmed the incorporation of valonia tannin into the backbone of the PU. The dispersion of valonia tannin and homogeneity of surface of the PU samples were confirmed by scanning electron microscopic (SEM) analysis. Chromaticity and colour difference further verified the colour depth and uniformity of the cured films. Thermogravimetric analysis (TGA) results indicated that the synthesised PU samples exhibited an improved thermal decomposition temperature. Particle size analysis, mechanical testing and water absorption of the synthesised PU samples further showed the effect of the cross-linked structure in the molecular chain segment. Moreover, the colour fastness and folding [flexing] resistance of the leather coating finished with synthesised PU was better than that of valonia tannin blending. Note de contenu : - MATERIALS AND METHODS : Materials - Synthesis of polyurethane - Preparation of polyurethane films and finished leather samples - Measurements - RESULTS AND DISCUSSION : FTIR spectral studies - Scanning electron microscope (SEM) analysis - Chromaticity and colour difference analysis - Particle size analysis - Thermal stability - Mechanical testing - Water and solvent resistance - Property analysis of leather coating - Table 1 : Chromaticity size analysis - Table 2 : The average particle size of the PU samples - Table 3 : Water and solvent resistance of PU samples - Table 4 : Properties of finished leather samples En ligne : https://drive.google.com/file/d/1vPbiP9usPOvkUanzxPqYIzf_EFe9o9MN/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32670 [article]

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Synthesis of tannic acid waterborne polyurethane in application for leather finishing / Haihang Luo in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 104, N° 3 (05-06/2020)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 104, N° 3 (05-06/2020) . - p. 129-135 Titre : Synthesis of tannic acid waterborne polyurethane in application for leather finishing Type de document : texte imprimé Auteurs : Haihang Luo, Auteur ; Yang Liu, Auteur ; Benyapathitiwong Ruj, Auteur ; Daolong Cai, Auteur ; Youjie He, Auteur Année de publication : 2020 Article en page(s) : p. 129-135 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Angle de contact Cuirs et peaux -- Finition Cuirs et peaux -- Propriétés mécaniques Polymères -- Propriétés thermiques Polymères -- Synthèse Polymères en émulsion Polyuréthanes Résistance à l'humidité:Résistance à l'eau Réticulants Tanins Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : More and more bio-based materials are used in waterborne polyurethanes (WPUs) due to their non-toxic and pollution-free advantages. In this paper, waterborne polyurethanes (WPU) were synthesised from 2, 4-Toluene diisocyanate (TDI-80) and polypropylene glycol (PPG, Mn=1000). Four kinds of WPU leather finishing agents (WPUO, WPU1, WPU2, WPU3) were prepared by adding different contents of the bio-based material tannic acid (TA) as a cross-linking agent. After a series of tests, the results showed that the thermal degradation temperature of WPU films and their tensile strength increased with the rise of TA content. When 0.6g TA was added, the tensile strength and thermodynamic stability reached the highest values, but the elongation at break was the lowest at the same time. The addition of the cross-linking agent TA reduced the hydrophilicity of the WPU film from% 40.8% to 16.2%. In the application of leather finishing, both dry and wet rubbing increased 1 to 2 grades through the introduction of TA and the folding fastness also improved significantly. The molecular chains were more closely arranged, and the distances between the molecules were also reduced on account of the incorporation of TA, resulting in a decrease in water vapour permeability. Based on this, the water contact angle of the finished leather has also increased from 68° to 99°. Note de contenu : - EXPERIMENTAL PROCEDURE : Materials - Synthesis of TA-based waterborne polyurethane - RESULTS AND DISCUSSION : FTIR spectroscopy - Thermal properties - SEM of the fracture surface of WPU - Emulsion size analysis - Mechanical properties - Water ressistance of WPU films and contact angle of leather surface - Applied properties En ligne : https://drive.google.com/file/d/1SoUJy9s76fuVQsPDJrLoe9qrl0ADdxNd/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=34241 [article]

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Ultrasonic removal of organic pollutants in tannery wastewater / Bi Shi in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVII, N° 3 (03/2002)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVII, N° 3 (03/2002) . - p. 98-101 Titre : Ultrasonic removal of organic pollutants in tannery wastewater Type de document : texte imprimé Auteurs : Bi Shi, Auteur ; Xinghai Gao, Auteur ; Zhongbing Lu, Auteur ; Youjie He, Auteur ; Guoxing Li, Auteur Année de publication : 2002 Article en page(s) : p. 98-101 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The effect of ultrasonic treatment on flocculating settling of tannery effluent, the reduction of COD in particular, was studied. The influence of the irradiation method, the duration of ultrasound and offer, and the prescription of coagulants on the efficiency of minimizing organic chemicals in wastewater were investigated. The results show that: (1) when waste water is treated only by ultrasound for 60 seconds, the removal rate of COD is 40.6%; (2) when total concentration of coagulants is increased to 100 mg/l, the greatest reduction of COD is achieved; (3) when wastewater is first treated with ultrasound for 60 seconds and then flocculated by coagulants, the reduction of COD is 10 - 37% higher than the controls without ultrasound. Thus, treatment of tannery wastewater with flocculating-settling technology can be effectively improved by ultrasound. En ligne : https://drive.google.com/file/d/13Tuy7K7WcmYAJ0GOWsnRSYeML-Vzev5G/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4314 [article]

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