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Fabrication and characterization of regenerated leather using chrome shavings as raw materials / Cuicui Ding in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 5 (05/2017)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXII, N° 5 (05/2017) . - p. 145-152 Titre : Fabrication and characterization of regenerated leather using chrome shavings as raw materials Type de document : texte imprimé Auteurs : Cuicui Ding, Auteur ; Min Zhang, Auteur ; Libo Dai, Auteur ; Yingying Qi, Auteur ; Ronghui Shi, Auteur ; Junhui Yang, Auteur Année de publication : 2017 Article en page(s) : p. 145-152 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse mécanique dynamique Analyse thermique Cuir reconstitué Microscopie électronique à balayage Polymères en émulsion Polyuréthanes Pressage à chaud Thermogravimétrie Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Regenerated leather billet (semi-finished product) was prepared via hot pressing with chrome shaving and environment-friendly polymer waterborne polyurethanes (WPU) as the materials. The influence of WPU/chrome shaving ratios (w/w) on the performance of the billet was investigated by mechanical property test, dynamic thermal mechanical analysis, thermogravimetric analysis, differential scanning calorimetry and field-emission scanning electron microscopy. Furthermore, the ability of heat storage and temperature regulation was endowed for the regenerated leather by the addition of paraffin microcapsules. The results showed that a strong interface interaction could be achieved for the regenerated leather billet, which could be due to the formation of hydrogen bonds and the entanglement between WPU and leather shavings. In this way, WPU/leather shaving composites with favorable mechanical properties, thermal stability, ability of heat storage and temperature regulation were obtained. Note de contenu : - MATERIALS AND METHODS : Materials - Sample preparation - Mechanical properties tests of regenerated leathers - Dynamic mechanical analysis (DMA) - Thermogravimetric analysis (TGA) - Field-emission scanning electron microscopy (FESEM) - Differential scanning calorimetry (DSC) - Dynamic thermal mechanical properties of regenerated leathers - Thermogravimetricc analysis of regenerated leathers - Morphology of regenerated leathers - DSC thermograms of regenerated leathers En ligne : https://drive.google.com/file/d/11sHls5bq_Vn7T2GYgPB0sR1XXAgRmOI6/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=28550 [article]

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The relationship between the structure of hyper-branched polymer and its effect on high exhaust chrome in reduced chrome tanning / Yao Qi in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 5 (05/2017)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXII, N° 5 (05/2017) . - p. 153-161 Titre : The relationship between the structure of hyper-branched polymer and its effect on high exhaust chrome in reduced chrome tanning Type de document : texte imprimé Auteurs : Yao Qi, Auteur ; Chenying Li, Auteur ; Henghui Huang, Auteur ; Hualin Chen, Auteur ; Bailing Liu, Auteur Année de publication : 2017 Article en page(s) : p. 153-161 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Chrome trivalent -- Absorption Cuirs et peaux -- Analyse Groupement carboxyle Oligomères Poids moléculaires Polydispersité Polymères -- Synthèse Polymères ramifiés Tannage au chrome Température de retrait Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Hyper-branched polymer (HBP) has been widely used as pretanning, tanning auxiliary and retanning agent in chrome tanning industry. However the effect of the structure of HBP including the degree of branching (DB) and molecular weight (Mw), on chrome tanning has seldom been studied. In this study a series of carboxyl-terminated hyper-branched oligomer (HBP) with different DB and Mw have been prepared and characterized by GPC and 1H-NMR for determining their molecular weight and its distribution, as well the DB. The effect of DB and Mw on the chrome uptake and shrinkage temperature (Ts) of hide was investigated. Experimental results showed that the chrome uptake was affected by both DB and Mw of developed HBP. HBP that possesses high DB and the Mw closed to 2000 Da, has endowed the obtained leather with higher Ts and chrome uptake. Moreover, the leather tanned with 3% chrome and 1.5% HBP possesses similar properties to the traditional tanning process using 6-8% chrome. Therefore, the carboxyl-terminated HBP presents a potential application as a tanning auxiliary in reduced chrome tanning due to it’s improving the absorption of chrome. Note de contenu : - MATERIALS AND METHODS : Chemicals and materials - Synthesis of the carboxyl-terminated hyper-branched oligomer - Chrome tanning - INSTRUMENTS AND MEASUREMENTS : Gel permeation chromatography (GPC) - Differential scanning calorimetry (DSC) - FT-IR spectra - H NMR - The acid value - Shrinkage temperature - Chrome uptake - Charactereization of HBP-x - FTIR of the HBP-1 - HNMR of the HBP-1 - Estimation of the DB - Molecular weights and polydispersity - Chrome uptake - Effect of DB on the chrome uptake - Effect of Mw on the chrome uptake - Reduced tanning with HBP En ligne : https://drive.google.com/file/d/1E-yNeSRgfe2iItWez_p55B8SmbCRWwzG/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=28551 [article]

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Zinc oxide (Zno) nanoparticles for enhancement of fastness properties in cationic finishing / RamKumar Kothandam in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 5 (05/2017)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXII, N° 5 (05/2017) . - p. 162-167 Titre : Zinc oxide (Zno) nanoparticles for enhancement of fastness properties in cationic finishing Type de document : texte imprimé Auteurs : RamKumar Kothandam, Auteur ; R. Jayavel, Auteur ; Sanjeev Gupta, Auteur Année de publication : 2017 Article en page(s) : p. 162-167 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cations Cuirs et peaux -- Finition Cuirs et peaux -- Propriétés mécaniques Flexion (mécanique) Nanoparticules Nanoparticules -- Synthèse Oxyde de zinc Résistance aux frottements humides Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Zinc oxide (ZnO) nanoparticles were synthesized by precipitation technique and used along with cationic finishes to improve the wet rub fastness properties and flexing resistance of coated leather. The morphology, composition, and structure of the ZnO nanoparticles were analyzed using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD). ZnO nanoparticles were dispersed in water and incorporated in different ratios in conventional Nitrocellulose lacquer emulsion topcoat formulation was coated on the leather surface by spray coater. ZnO nanoparticles coated leather samples exhibited improved wet and dry rub fastness and flexing resistance property. Optimum quantity up to 2-4 g/L of ZnO nanoparticles in the season was desirable for upgrading the value of leathers. ZnO nanoparticles in cationic finishing can be highly beneficial for up gradation of low-grade crust with improved fastness properties without affecting its natural look and feel. Note de contenu : - EXPERIMENTAL : Materials - Synthesis of Zno nanoparticles - Preparation of conventional base coat. Leather finishing formulation - Preparation of top coat formulation with incorporation of Zno nanoparticles - RESULTS AND DISCUSSION : X-ray diffraction spectroscopy (XRD) analysis - Scanning electron microscopy (SEM) - Energy-dispersive X-ray (EDAX) peaks of ZnO nanoparticles - Elemental composition analysis - Determination of applied physical properties of ZnO nanoparticles coated leather - Wet and dry rub analysis - Flexing resistance En ligne : https://drive.google.com/file/d/1YD1JBGZfQ8d5PuxnxYICMpqxqRIOd0Ep/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=28552 [article]

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Determination of formaldehyde content in leather : EN ISO 17226 standard. Influence of the agitation method used in the initial phase of formaldehyde extraction / Albert M. Manich in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXII, N° 5 (05/2017)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXII, N° 5 (05/2017) . - p. 168-179 Titre : Determination of formaldehyde content in leather : EN ISO 17226 standard. Influence of the agitation method used in the initial phase of formaldehyde extraction Type de document : texte imprimé Auteurs : Albert M. Manich, Auteur ; Sara Cuadros, Auteur ; Joaquim Font, Auteur ; Anna Bacardit, Auteur ; Felipe Combalia, Auteur ; Agusti Marsal, Auteur Année de publication : 2017 Article en page(s) : p. 168-179 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Analyse quantitative (chimie) Cuir -- Teneur en formaldéhyde Cuirs et peaux -- Analyse Cuirs et peaux -- Normes Extraction (chimie) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Given the carcinogenic character of formaldehyde, it should be reliably determined in any substrate. The EN ISO 17226 Standard is the Official Method to quantify formaldehyde in leather. However, some misunderstandings may arise from the practical conditions given by the Standard for the extraction of formaldehyde. Two agitation methods (magnetic agitation and reciprocal linear agitation), which fulfill the conditions of the Standard, have been used for the extraction of formaldehyde in twenty two samples of wet-blue split leather treated with resins synthesized with formaldehyde and with/without the addition of vegetable compounds. The agitation method influences the formaldehyde content and differences between the agitation methods depend on the formaldehyde resins and vegetable compounds applied. Magnetic agitation leads to formaldehyde contents that are 26% greater than those obtained when the reciprocal linear agitation method is used. Major brands specify allowable limits for formaldehyde content, which depend on the user (adult or babies) and whether the article is in direct contact with the skin. A high percentage of disagreement (33.3%) has been observed between the agitation methods in fulfilling the allowable limits. One-third of the formaldehyde content results that fulfilled the allowable limits with the reciprocal linear agitation method failed when the magnetic method was applied. The situation urges the clarification of the shaking method in the EN ISO 17226 Standard to avoid the high level of contradictory results between methods that meet the agitation conditions of the Standard. Note de contenu : - MATERIALS - METHODS : Determination of formaldehyde in leather - Analysis of formaldehyde content in formaldehyde resins - Analysis of tannins and non-tannins in vegetable compounds - regression analysis - RESULTS AND DISCUSSION : Influence of the formaldehyde content (low, A or high, B) of the melamine-formaldehyde resin on the formaldehyde content (FC) of the treated leather samples extracted with the two agitation methods - Influence of the formaldehyde content (low, A or high, B) of the dicyandiamide-formaldehyde resin on the formaldehyde content (FC) of the treated leather samples extracted with the two agitation methods - Influence of the resin type (MF and DCDF) of low formaldehyde content - Influence of the resin type (MF and DCMF) of high formaldehyde content - Influence of the vegetable compounds on the linear regression between the formaldehyde content of leather samples extracted by the two agitation methods - Influence of the shaking methods on the formaldehyde content of samples treated with formaldehyde-based resins with and without vegetable compounds - Influence of the shaking method on failure/acceptance of formaldehyde content results in relation to allowable limits En ligne : https://drive.google.com/file/d/1OK9UDZ-q6PFVeaXvrzquTUioqyzJzfDi/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=28553 [article]

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