Comparative retanning performance of ecofriendly melamine resins produced using different condensing agents / Muhammad Naveed Ashraf in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 105, N° 3 (05-06/2021)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 105, N° 3 (05-06/2021) . - p. 140-152 Titre : Comparative retanning performance of ecofriendly melamine resins produced using different condensing agents Type de document : texte imprimé Auteurs : Muhammad Naveed Ashraf, Auteur ; Shahzad Maqsood Khan, Auteur ; Shahid Munir, Auteur ; Rashid Saleem, Auteur Année de publication : 2021 Article en page(s) : p. 140-152 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux -- Propriétés organoleptiques Mélamine sulfonée Mélamine La mélamine, de nom chimique 1,3,5-triazine-2,4,6-triamine, est parfois dénommée cyanuramide ou cyanurotriamine. Sa formule brute est C3H6N6. Les "résines mélamine-formaldéhyde" ou "mélamine-formol" (sigle MF) sont appelées "mélamine" dans le langage courant. Elles font partie de la famille des aminoplastes qui regroupe des résines thermodurcissables aminées, issues d'un comonomère tel l'urée ou la mélamine, parfois le thiocarbamide, le cyanamide hydrogène ou le dicyandiamide ; le second comonomère étant le formaldéhyde. Produits de condensation (chimie) Retannage Tannage synthétique Index. décimale : 675 Technologie du cuir et de la fourrure Résumé : Formaldehyde has been a famous raw material for production of amino resins used in leather processing however; the proven carcinogenic hazards of formaldehyde contravene regulations are restricting the sale of leather goods with regard to human contact. In this study sulfonated melamine based resins were produced by using condensing agents other than formaldehyde, for example furfural, glyoxal, methylglyoxal and glutaraldehyde. Synthesised formaldehyde-free melamine resins were studied for determination of their molecular weights, thermal stability by TGA and spectroscopic studies using FTIR. Synthesised resins were used in leather retanning for investigation of their mechanical and organoleptic properties in comparison with leather samples based on a commercial resin. The effects of melamine resins on the fibrous structure of collagen were examined by SEM. Leather pieces were analysed for estimation of free formaldehyde contents and the pollution load of the retanning wastes was also investigated. The prepared resins conferred improved mechanical and organoleptic characteristics to the resulting leather compared to the control but the results produced by MGLSNA and MGSNA resins were more prominent. Leather produced from each resin sample was formaldehyde free. SEM images of the leather revealed the presence of fine grains with improved fibrous collagen structure especially for MGLSNA and MGSNA. Pollution load reduction efficiency of newly developed resins was improved in comparison with control indicating their better uptake and fixation in collagen fibres. Overall, all four novel resins produced formaldehyde-free leather with improved retanning and thermal properties but the results produced by MGLSNA and MGSNA resins were better due to introduction of more reactive sites and aromatic sulfonation agents. Note de contenu : - EXPERIMENTAL PROCEDURE : Chemicals and apparatus - Synthesis of sulfonated melamine resins - RESULTS AND DISCUSSION : Synthesis of sulfonated melamine resins - Physical characteristics of sulfonated melamine resins - Molecular weight determination of sulfonated melamine resins - Comparative application of sulfonated melamine resins on leather - Mechanical properties of leather retanned with sulfonated melamine resins - Organoleptic properties of leather retanned with sulfonated melamine resins - Characterisation of retanned leather by SEM - Determination of free formaldehyde content in leather - Thermo gravimetric analysis of sulfonated melamine resins - FTIR analysis - Wastewater analysis of retanning bath - Table 1 : Mole ratio and physical characteristics of sulfonated melamine resin prepared with different condensing agents - Table 2 : Dependence of the flow time, relative viscosity, specific viscosity, δ = ηsp - inηr and δ/c2 at different concentrations of SMFr resin - Table 3 : Dependence of the concentration of novel resins of study on δ/c2 - Table 4 : Leather processing recipe, materials and conditions - Table 5 : Mechanical properties of leather retanned with sulfonated melamine resins - Table 6 : Comparative pollution load efficiency of sulfonated melamine resins En ligne : https://drive.google.com/file/d/1N5Wt_oi9uVzToJ_7z1L_jwRfqTgOlm5M/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=35834 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
22745	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Contribution à l'étude du mécanisme de formation d'un revêtement de polysilicate d'éthyle sur support ferreux grenaillé / Michel Ecuyer / 1987

Titre : Contribution à l'étude du mécanisme de formation d'un revêtement de polysilicate d'éthyle sur support ferreux grenaillé Type de document : texte imprimé Auteurs : Michel Ecuyer, Auteur ; Georges Vallet, Directeur de thèse ; Université Claude Bernard (Lyon), Organisme de soutenance Année de publication : 1987 Importance : 115 p. Présentation : ill. Format : 30 cm Note générale : Bibliogr. Langues : Français (fre) Catégories : Fer Hydrolyse Métaux -- Revêtements Polysilicate d'éthyle Produits de condensation (chimie) Revêtements organiques Silicates Thèses et écrits académiques Index. décimale : 667.9 Revêtements et enduits Note de contenu : - Présentation des polysilicates d'alkyle et de certaines de leurs utilisations industrielles - Texture des gels de polysilicate d'alkyle en fonction des conditions de mise en oeuvre - Etude des interactions entre le revêtement de polysilicate d'éthyle et le support ferreux - Approche macroscopique de la formation d'un revêtement de polysilicate d'éthyle - Influence du fer sur la structure d'un revêtement de polysilicate d'éthyle et sur la transestérification d'alkxysilanes en solution Thèse : Thèse. Spécialité matériaux macromoléculaires - Université Lyon 1 - 1987 Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=1067

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
0710	TH/1987/ECU	Thèse, mémoire, etc...	Bibliothèque principale	Documentaires	Disponible

Etudes des propriétés dispersantes des produits de condensation des acides naphtalène sulfoniques / Hamid Aleboyeh in L'ACTUALITE CHIMIQUE, N° 6 (06/1999)  

[article]  inL'ACTUALITE CHIMIQUE > N° 6 (06/1999) . - p. 10-15 Titre : Etudes des propriétés dispersantes des produits de condensation des acides naphtalène sulfoniques Type de document : texte imprimé Auteurs : Hamid Aleboyeh, Auteur ; Serge Walter, Auteur ; Néji Ladhari, Auteur ; Azam Aleboyeh, Auteur Année de publication : 1999 Article en page(s) : p. 10-15 Note générale : Bibliogr. Langues : Français (fre) Catégories : Adsorption Agents dispersants (chimie) Colorants Produits de condensation (chimie) Sulfoniques, Acides Index. décimale : 547 Chimie organique : classer la biochimie à 574.192 Résumé : This work deals with the use of the dinaphtylmethanedisulfonic acid sodium salt as a dispersing agent for dyestuffs. Is it produced naphtalène sulfonation in oleum, followed by condensation with formaldehyde and subsequent neutralization by caustic soda. The properties of the obtained products are discussed as dependent on processing conditions. The origins of the main parameters ruling the dispersant effect, dispersion stability and dying power on polyester material are examined. The results show that the presence of remaining naphtalene does no modify significantly the adsorption speed on dyestuff particles. The samples made of naphtalene-2 sulfonic acid show excellent dispersant properties. Naphatalene-1 sulfonic acid derivatives show higher adsorption rates. The simultaneous presence of both acids thus leads to good properties of the final product. With high molecular weight, high condensation degrees result in very good absorbtion behaviour of the dyestuff in textile fibers. En ligne : https://new.societechimiquedefrance.fr/numero/etudes-des-proprietes-dispersantes [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=7562 [article]

Réservation

Réserver ce document

Exemplaires (2)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
002147	-	Périodique	Bibliothèque principale	Documentaires	Disponible
002148	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Melamine ethoxylates as novel formaldehyde free replacements of resin re-tanning agents / Jochen Ammenn in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CXVII, N° 7 (07/2022)  

[article]  inJOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA) > Vol. CXVII, N° 7 (07/2022) . - p. 296-301 Titre : Melamine ethoxylates as novel formaldehyde free replacements of resin re-tanning agents Type de document : texte imprimé Auteurs : Jochen Ammenn, Auteur Année de publication : 2022 Article en page(s) : p. 296-301 Note générale : Bibliogr. Langues : Américain (ame) Catégories : Agents de tannage Cuirs et peaux de bovins Ethoxylates de mélamine Formaldéhyde -- Suppression ou remplacement Produits de condensation (chimie) Retannage Tannage synthétique Wet-blue (tannage) Peau tannée au chrome (le chrome donne une couleur bleue) Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Melamine urea formaldehyde condensates or resin re-tanning agents are commonly used in the leather industry. They give rise to homogeneous filling, are easily and widely applicable, but generally contribute to free formaldehyde, measurable in emission or extraction methods. Many projects to resolve this issue have been carried out. The weakness of the resin re-tanning is the reversibility of the bond formation between formaldehyde and two amino groups. The formaldehyde forms a methylene group after condensation with two amino groups and releases water. This methylene group can be hydrolyzed under acidic conditions to release formaldehyde again, reversing the synthesis. Melamine ethoxylates were found to be a formaldehyde free, stable, and easily applicable alternative. Besides the fact that they are made without formaldehyde, it proved to be possible to incorporate renewable components into their synthesis, giving rise to an even more sustainable product. Another sustainable aspect of this chemistry is the delivery of the potential product as a concentrated liquid versus most resin re-tanning agents being placed into the market as spray dried powders, consuming significant amounts of energy in the process. Melamine ethoxylates show advantages in application on leather in comparison with classical resin re-tanning agents. An insight into the scope of application will be given, showing that melamine ethoxylates can be considered a formaldehyde free replacement for resin re-tanning agents. Note de contenu : - Melamine urea formaldehyde condensates - Melamine ethoxylates - Table 1 : Screening results of the re-tanning of bovine wet blue of different melamine ethoxylates against a standard melamine urea formaldehyde condensate and polyethylene glycol : + = better ; 0 = similar ; — = worse - Table 2 : Re-tanning of bovine wet blue with the optimized melamine ethoxylate against a standard melamine urea formaldehyde condensate : + = better; 0 = similar ; - = worse - Table 3 : Results of re-tanning of bovine wet blue or wet white with melamine ethoxylates in a mixed recipe compared to a melamine urea formaldehyde condensate in the mixed recipe : + = better; 0 = similar; - = worse En ligne : https://drive.google.com/file/d/1cuWtS0wR-6zJregVnQ4eK0FqHZOfhLNC/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=37822 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
23515	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Preparation of formaldehyde-free melamine resins using furfural as condensing agent and investigation of their retanning performance / Muhammad Naveed Ashraf in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 103, N° 5 (09-10/2019)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 103, N° 5 (09-10/2019) . - p. 272-278 Titre : Preparation of formaldehyde-free melamine resins using furfural as condensing agent and investigation of their retanning performance Type de document : texte imprimé Auteurs : Muhammad Naveed Ashraf, Auteur ; Shahzad Maqsood Khan, Auteur ; Shahid Munir, Auteur ; Rashid Saleem, Auteur Année de publication : 2019 Article en page(s) : p. 272-278 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Cuir -- Teneur en formaldéhyde Cuirs et peaux -- Analyse Cuirs et peaux -- Propriétés organoleptiques Furfural Mélamine La mélamine, de nom chimique 1,3,5-triazine-2,4,6-triamine, est parfois dénommée cyanuramide ou cyanurotriamine. Sa formule brute est C3H6N6. Les "résines mélamine-formaldéhyde" ou "mélamine-formol" (sigle MF) sont appelées "mélamine" dans le langage courant. Elles font partie de la famille des aminoplastes qui regroupe des résines thermodurcissables aminées, issues d'un comonomère tel l'urée ou la mélamine, parfois le thiocarbamide, le cyanamide hydrogène ou le dicyandiamide ; le second comonomère étant le formaldéhyde. Polymères -- Synthèse Produits de condensation (chimie) Retannage Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Sulfonated amino resins are an important class of polymers which are used as retanning agents in the leather industry. There is challenge for such resins to be synthesised without formaldehyde to satisfy the strict regulation in leather goods. In this work, formaldehyde-free melamine based retanning agents have been synthesised by acid catalysed process using furfural as condensing agent and sodium metabisulfite as the sulfonating agent. Sulfonated melamine furfural (SMFr) resins were synthesised using different molar ratio of melamine, sodium metabisulfite and furfural. Stable and water-soluble resins were produced without etherification. The sodium metabisulfite to melamine ratio (SMB/M) was changed from 0.5-2.0 and furfural to melamine mole ratio (Fr/M) was varied from 2-6. The viscosity behaviour of the produced resins wâs evaluated with the increasing trend of sulfonation and increasing mole ratio of furfural to melamine. Functional group analysis and conversion of reactants into product was elucidated by FTIR. Synthesised formaldehyde-free resins (SMFr) were comparatively evaluated as retanning agents on goatskin wet-blue against a commercially available sulfonated melamine formaldehyde (SMF) resin. The retanning performance of synthesised resins was studied and found better than that of the commercial SMF resin. Note de contenu : - EXPERIMENTAL PROCEDURE : Materials and equipment - Preparation of SMFr resin - RESULTS AND DISCUSSION : Synthesis of SMFr resin - Viscosity trend of resins - Resin application on leather as retanning agent - Quantitative determination of free formaldehyde content in leather - Organoleptic properties of retanned leather - SEM examination (JEOL 6490) - Structure elucidation/FTIR spectroscopy analysis of SMFr resin En ligne : https://drive.google.com/file/d/1tehL2heU-liowrx614fHL9jzpSdLCcXB/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=33003 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
21222	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Studies on the development of leathers from formaldehyde-free melamine syntan / Swarna Vinodh Kanth in JOURNAL OF THE AMERICAN LEATHER CHEMISTS ASSOCIATION (JALCA), Vol. CVII, N° 5 (05/2012)  

Permalink

---

1 (1 - 6 / 6)