Application of carboxyl-functionalized epoxy resin in the leather tanning process / Bin Lyu in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXIII, N° 7 (07/2018)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXIII, N° 7 (07/2018) . - p. 225-231 Titre : Application of carboxyl-functionalized epoxy resin in the leather tanning process Type de document : texte imprimé Auteurs : Bin Lyu, Auteur ; Li Yajuan, Auteur ; Dangge Gao, Auteur ; Jianzhong Ma, Auteur ; Lv Leihong, Auteur Année de publication : 2018 Article en page(s) : p. 225-231 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Cuir -- Teneur en chrome hexavalent Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux -- Propriétés physiques Détérioration enzymatique Douceur (toucher) Eaux usées -- Teneur en chrome hexavalent Epoxydes Groupement carboxyle Polymères -- Synthèse Réactions chimiques Stabilité hydrothermale Tannage Température de retrait Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Chrome tanning is widely used in the tanning process ; however, it can cause environmental pollution. Leather tanned with epoxy resin was considered as a more environmentally friendlyprocess, but it takes as long as five days for reaction, and results in poor performance of leather. The aim of the present study was to tan leather collagen with a carboxyl-functionalized epoxy resin, which was thought to be an eco-friendly tanning process and the reaction time was shortened to 12h. The reaction between carboxyl-functionalized epoxy resin and leather collagen can be divided into two stages, the reaction of epoxy group with leather collagen and the reaction of carboxyl group with leather collagen. The influences of tanning conditions (medium pH, epoxy resin amount and reaction time) on the properties of tanned leather were also discussed. In the first stage, the epoxy group was reacted with leather collagen in basic conditions. The results showed that the carboxyl-functionalized epoxy resin could better penetrate into the leather fibers when the pH value was 8.5, and the best effect of tanned leather collagen was found using reaction condition of pH 7.0. In the second stage, it was the reaction of carboxyl group to leather collagen in acid conditions, and the best effect was found under the condition of pH was 3.5. Meanwhile, it provided a better tanning effect when the carboxyl-functionalized epoxy resin amount was 6% and the reaction time was 12h. The chrome-less tanning process that carboxyl-functionalized epoxy resin combination with 3% chrome was studied. The results showed that the hydrothermal stability and strength properties of leather tanned by carboxyl-functionalized epoxy resin with 3% chrome were close, even superior, to those of the leather produced by conventional chrome tanning with 8% chrome. Note de contenu : - MATERIALS AND METHODS : - Material - Methods : Synthesis of the carboxyl-functionalized epoxy resin - Tanning methodology - Testing and characterization : Shrinkage temperature - Thickness increment ratio - Mechanical properties - Softness - Enzymatic degradation - Chrome content in leather and waste water - Calculation - RESULTS : - Tanning conditions of carboxyl-functionalized epoxy resin pH : The amount of tanning agent - Chrome-less tanning results : SEM topography of the leather - Physical properties - Mechanical properties - Softness - Enzymatic degradation - Chrome content in leather and waste water En ligne : https://drive.google.com/file/d/1zAn7Cgd6nhD2xonUrhpGkK5uE09EybTG/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=30830 [article]

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Diffusion and reaction behavior of proteases in cattle hide matrix via FITC labeled proteases / Jianzhong Ma in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIX, N° 5 (05/2014)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIX, N° 5 (05/2014) . - p. 138-145 Titre : Diffusion and reaction behavior of proteases in cattle hide matrix via FITC labeled proteases Type de document : texte imprimé Auteurs : Jianzhong Ma, Auteur ; Xueyan Hou, Auteur ; Dangge Gao, Auteur ; Jing Zhang, Auteur Année de publication : 2014 Article en page(s) : p. 138-145 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Collagène -- Détérioration Cuirs et peaux de bovins Diffusion (physique) Hydrolyse enzymatique Isothiocyanate de fluorescéine L'isothiocyanate de fluorescéine (FITC, fluorescein isothiocyanate en anglais) est un dérivé de la fluorescéine utilisée dans un large spectre d'applications comme la cytométrie en flux. Le FITC est une molécule de fluorescéine fonctionnalisée avec un groupe réactif isothiocyanate (-N=C=S), remplaçant un atome d'hydrogène sur le cycle le plus bas de la structure. Ce dérivé réagit avec les nucléophiles comme les groupes amines et sulfhydryles des protéines. Un groupe fonctionnel succinimidyle-ester greffé au noyau fluorescéine, créant le NHS-fluorescéine, forme un autre dérivé commun réagissant avec les amines, possédant une plus grande spécificité envers les amines primaires en présence d'autres nucléophiles. Le FITC possède un pic d'excitation et d'émission à 495 nm et 521 nm respectivement. Comme la plupart des fluorochromes, il est sujet au photobleaching. Par conséquent, des dérivés de la fluorescéine tels que l'Alexa 488 et le DyLight 488 ont été optimisés pour des applications chimiques et biologiques nécessitant une plus grande photostabilité, une plus grande intensité de fluorescence ou l'ajout de groupements différents. Peptidases Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Enzymes play an important role in the biological treatment of animal skin collagen in the leather making process. In this work, three proteases (2709, LimeG and SoakL) with different molecular weight were used in the treatment of cattle hide. Protein and hydroxyproline absorbance was measured to evaluate the treatment effectively. Proteases labeled by Fluorescein Isothiocyanate (FITC) were used to treat the cattle hide to observe the diffusion and reaction behavior of proteases in cattle hide matrix. The results indicate that when the cattle hide was treated with smaller molecular weight protease, the degradation degree of the protein and collagen was more than that of the cattle hide treated with larger molecular weight protease. The fluorescence microscopy images demonstrate that during the early stages, proteases chiefly diffused into the cattle hide matrix through pores and hair follicles, and then diffused into the inner layer via hair follicles to hydrolyze inter-fibrillary proteins for opening up collagen fibers. In the present investigation, a visible assessment for the diffusion and reaction behavior of proteases in the enzymatic treatment of cattle hide matrix was reported. Note de contenu : - MATERIALS AND METHODS : Materials - Instrumentation - Determination of the protease activity - Enzymatic treatment of cattle hide matrix - FITC labeled protease - Analysis - RESULTS AND DISCUSSION : Enzymatic treatment of cattle hide matrix - The effect of FITC on the activity of FITC labeled protease - Effect of molecular weights of protease on the diffusion - Diffusion and reaction mechanism of proteases in cattle hide matrix En ligne : https://drive.google.com/file/d/1QDPKDq7Hvzq6ren7nS9eHkiT-NiXMA66/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21285 [article]

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Effect of the composition of vinyl polymer tannages on the physical properties of leather / Jianzhong Ma in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVI, N° 1 (01/2001)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. XCVI, N° 1 (01/2001) . - p. 14-22 Titre : Effect of the composition of vinyl polymer tannages on the physical properties of leather Type de document : texte imprimé Auteurs : Jianzhong Ma, Auteur ; Zongsui Yang, Auteur ; Cheng-Kung Liu, Auteur ; Wei Wang, Auteur Année de publication : 2001 Article en page(s) : p. 14-22 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : The effects of the composition of vinyl polymer tannages on the physical properties of leather have been systematically studied with a statistical two-power regression orthogonal design1. Fracture energy was measured along with tensile strength, elongation and tensile modulus for a wide variety of syntan treated pigskin leathers. Eight monomers: acrylonitrile (AN) , acrylamide (AM), methyl acrylic acid (MAA), methyl methacrylate (MMA), vinyl acetate (VAc), methyl acrylate (MA), ethyl acrylate (EA), and butyl acrylate (BA) were chosen respectively to copolymerize with acrylic acid (AA) to form the corresponding copolymers. Tests showed the excellent physical properties of leather treated by the hexa-copolymer composed of AA, AN, AM, MMA, VAc and EA. After performing the retanning application test by using these copolymers as tannages, the physical properties of the retanned leather samples, such as tensile strength, elongation at break, toughness (fracture energy), and stiffness (Young's modulus ) were measured. The results showed the comonomer ratio of vinyl polymer tannages can greatly affect the physical properties of leather. If the comonomer ratio of the hexa-copolymer composed of AA, AN, AM, MMA, VAc and EA is optimized, the hexa-copolymer tannages can offer significant improvements in the tensile strength, elongation at break, toughness (fracture energy), and softness of the leather samples. En ligne : https://drive.google.com/file/d/1nmu2dgN8w5yB61JR8Em4cf57luLrS-ku/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4401 [article]

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Effects of chain transfer agents on properties of AA/BA/AM copolymer retanning agents / Bin Lyu in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 101, N° 1 (01-02/2017)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 101, N° 1 (01-02/2017) . - p. 10-15 Titre : Effects of chain transfer agents on properties of AA/BA/AM copolymer retanning agents Type de document : texte imprimé Auteurs : Bin Lyu, Auteur ; Jia Lu, Auteur ; Jianzhong Ma, Auteur ; Dangge Gao, Auteur ; Dong Ma, Auteur Année de publication : 2017 Article en page(s) : p. 10-15 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Copolymère acide acrylique acrylate de butyle acrylamide Cuirs et peaux -- Propriétés mécaniques Diffractométrie de rayons X Fourier, Spectroscopie infrarouge à transformée de Microscopie électronique à balayage Polyaddition Polymères -- Analyse Retannage Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : The retanning process is one of the most important processes in leather production and which plays a vital role in the modern leather industry. In this paper, copolymers based on acrylic acid (AA), butyl acrylate (BA) and acrylamide (AM), were prepared by free radical polymerization. Chain transfer agents were added during the synthesis process to control the molecular weight of the copolymer. The copolymers with different amounts of chain transfer agent were tested for their molecular weight and other properties. The copolymers were analysed using XRD, GPC and FT-IR. Leathers were retanned with different copolymers and the mechanical properties, and SEM of retanned leather were also examined. The results showed that the increased molecular weight of the copolymers decreased the crystallinity, the functional groups of copolymers did net change significantly when the dosage of chain transfer agents increased. When the amount of chain transfer agents was increased, the copolymer had a smaller molecular weight and the retanned leather showed better elongation at break. When the copolymer molecular weight was larger, the tensile strength and tear strength of retanned leather increased. This is important to help select the appropriate molecular weight acrylic retanning agent for different styles of leather products. Note de contenu : - EXPERIMENTAL PROCEDURES : Materials - Synthesis of the poly AA/BA/AM copolymer - Preparation of leather - Characterization - FT-IR analysis - Mechanical properties - RESULTS AND DISCUSSION : Characteristics of the prepared copolymer solution - Gel permeation chromatography (GPC) - FT-IR analysis of the prepared copolymers solution - XRD analysis of the prepared copolymers - Scanning electron microscope (SEM) - Mechanical properties En ligne : https://drive.google.com/file/d/1w2kH_N0PovJ81YRA4Y7GYM4W1wDFxHJQ/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=27983 [article]

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Elastiticy studies on leather retanned with various types of acrylic polymers / Jianzhong Ma in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CIII, N° 11 (11/2008)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CIII, N° 11 (11/2008) . - p. 363-369 Titre : Elastiticy studies on leather retanned with various types of acrylic polymers Type de document : texte imprimé Auteurs : Jianzhong Ma, Auteur ; Hua Lu, Auteur Année de publication : 2008 Article en page(s) : p. 363-369 Note générale : Bibliogr. Langues : Américain (ame) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Different acrylic polymer retanning agents were synthesized with acrylic acid as the primary monomer and eight other acrylate monomers (MAA-methyl acrylic acid, EA-ethyl acrylate, BA-butyl acrylate, VAc-vinyl acetate, MA-methyl acrylate, AM-acrylamide, IA-Itaconic acid, HEA-2-hydroxyethyl acrylate) as commoners. The eight copolymers were applied in the retanning process separateley and the elasticity of the resultant leather was discussed. The results showed that the leather elasticity could be tested by calculating young's modulus of the elastic deformation, which ws a variable region on the load-displacement curve, and young's modulus of the elastic deformation could serve as an independent parameter in characterizing leather's physical properties. The relation between the elasticity and the dosage of copolymer was discussed, and it revealed that every comonomer had a proper dosage at which level the resultant leather showed the lowest young's modulus. Then the effects of the eight comonomers on leather elasticity were compared under the same condition. It showed that the soft comonomers, BA and EA, contributed more in leather elasticity than other selected comonomers. En ligne : https://drive.google.com/file/d/1M03xfreplpgebWEsh1KSuRfyOjukyXzr/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=3022 [article]

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High performance strain sensor based on leather activated by micro-cracking conductive layer / Jianzhong Ma in COLLAGEN AND LEATHER, Vol. 5 (2023)  

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Influence of alcohols on stability and mechanical properties of polyacrylate coating material / Dangge Gao in JOURNAL OF COATINGS TECHNOLOGY AND RESEARCH, Vol. 12, N° 6 (11/2015)  

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Polyurethane/polyacrylate/silica nanocomposite prepared by seeded emulsion polymerization and the properties of finished leather / Yan Bao in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 97, N° 6 (11-12/2013)  

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Preparation and application of a multi-functional tanning agent - (MTA) / Jianzhong Ma in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 79, N° 2 (03-04/1995)  

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Preparation and characterisation of sulfonated calix[4]arene and its application in chrome-free tanning / Yongxiang Zhou in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 102, N° 4 (07-08/2018)  

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Preparation and properties of a methacrylic acid-co-modified maleic anhydride/montmorillonite nanocomposite for tanning / Yan Bao in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 95, N° 4 (07-08/2011)  

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Study of soft side upper leather retanned with multi-functional tanning agent - MTA / Jianzhong Ma in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 79, N° 4 (07-08/1995)  

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Synthesis of modified poly(acrylic acid-acrylonitrile) retanning agent with mannich reaction and its application / Huaxiang Yang in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. XCVI, N° 11 (11/2001)  

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The correlation between composition of vinyl polymer tannages and their properties / Wei Wang in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 85, N° 4 (07-08/2001)  

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The correlation between the comonomer ratios of vinyl polymer tannages and their application properties / Jianzhong Ma in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 86, N° 2 (03-04/2002)  

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The interaction between collagen and aldehyde-acid copolymer/MMT nano-composite / Yan Bao in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 94, N° 2 (03-04/2010)  

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The preparation and application of a montmorillonite-based nanocomposite in leather making / Jianzhong Ma in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 87, N° 4 (07-08/2003)  

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