Comparative study of retanning properties of melamine-glyoxal resins produced by different sulfonating agents / Muhammad Naveed Ashraf in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 106, N° 5 (09-10/2022)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 106, N° 5 (09-10/2022) . - p. 205-214 Titre : Comparative study of retanning properties of melamine-glyoxal resins produced by different sulfonating agents Type de document : texte imprimé Auteurs : Muhammad Naveed Ashraf, Auteur ; Shahzad Maqsood Khan, Auteur ; Shahid Munir, Auteur ; Rashid Saleem, Auteur Année de publication : 2022 Article en page(s) : p. 205-214 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Composés organiques -- Synthèse Cuirs et peaux -- Propriétés mécaniques Eaux usées -- Analyse Etudes comparatives Mélamine glyoxal Retannage Tannage synthétique Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Amino resins have many applications including leather retanning. Being condensation products of formaldehyde, amino resins are one of the sources of free formaldehyde in leather. ln this work novel glyoxylated melamine resins were produced to make formaldehyde-free leather. The optimised process of synthesis was used to produce stable resins which were able to polymerise further in situ at retanning pH conditions. Water solubility of the resins was achieved by using various aromatic sulfonating agents including, orthanilic acid (ONA), metanilic acid (MNA), sulfanilic acid (SNA) and aniline 2,5-disulfonic acid (ADS). Synthesised resins were used in leather retanning to evaluate their comparative mechanical properties, organoleptic properties, free formaldehyde content and SEM analysis. The effluent of each retanning bath was also analysed for pollution load studies. All the resins showed improvements in mechanical and organoleptic properties in comparison with a commercial melamine resin but, the novel resin MGSNA exhibited remarkable results. Estimation of free formaldehyde content showed absence of free formaldehyde content in leather and retanning effluent of all the novel resins. Determination of COD, TDS and TSS of effluent confirmed a significant reduction in pollution load due to improved exhaustion of resins attributed to their in-situ polymerisation in collagen fibres to enhance their fixation. SEM analysis of leather confirmed improvements in retanning results due to formation of more orderly arranged networks of collagen fibres. Moreover, the introduction of an aromatic ring in the resin structure resulted in improved thermal stability of the resins. The results indicate that this development is remarkable for production of formaldehyde-free leather with improved retanning properties along with reduction in water pollution. This work also addresses the carcinogenic effects of formaldehyde. Note de contenu : - EXPERIMENTAL PROCEDURE : Chemicals and apparatus - Synthesis of novel melamine-glyoxal resins - RESULTS AND DISCUSSION : Synthesis of resins - Leather applications of various novel glyoxal based melamine resins - Mechanical properties of leather reatanned with glyoxal-based melamine resins - Orgnoleptic properties of the leather retanned with glyoxal-based melamine resins - SEM analysis - Quantitative estimation of free formaldehyde content in retanned leather - Thermogravimetric analysis - Effluent analysis - Structural elucidation - Table 1 : Mole ratio and physical characteristics of prepared novel melamine resins - Table 2 : Leather processing materials, conditions and recipe - Table 3 : Mechanical properties of leather retanned with glyoxal based melamine resins - Table 4 : Comparative study of effluent produced from retanning baths of synthesised resins En ligne : https://drive.google.com/file/d/1d731nM2Y_RzuR-xX0DT3EX7AtII9e3uS/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38195 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
23641	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Melamine glyoxal resin as a retanning agent - preparation and application / Xie Heng in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 98, N° 1 (01-02/2014)  

[article]  inJOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 98, N° 1 (01-02/2014) . - p. 17-22 Titre : Melamine glyoxal resin as a retanning agent - preparation and application Type de document : texte imprimé Auteurs : Xie Heng, Auteur ; Sun Qingyong, Auteur ; Xuepin Liao, Auteur ; Bi Shi, Auteur Année de publication : 2014 Article en page(s) : p. 17-22 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Caractérisation Cuir -- Teneur en formaldéhyde Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux -- Propriétés organoleptiques Cuirs et peaux -- Propriétés physiques Formaldéhyde -- Suppression ou remplacement Fourier, Spectroscopie infrarouge à transformée de Mélamine glyoxal Retannage Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Amino resins have played an important role in the manufacture of leather due to their outstanding filling and dyeing properties. However, a traditionally prepared amino resin usually contains free formaldehyde, which is strictly restricted in leather products. With increasing awareness of potential health problems with formaldehyde, there is a growing demand for formaldehyde-free leathers in the global leather market. In this study, a formaldehyde-free amino resin was synthesized by using glyoxal as condensing agent, and its retanning properties were investigated. It was found that the glyoxal can be used to replace formaldehyde to synthesize an amino resin, and the optimal reaction conditions were that the molar ratio of melamine to glyoxal was 1:6, reaction temperature was 333K and reaction time was 3 hours. Retanning experiments with the prepared amino resin indicated that its retanning properties, including fullness, softness, general appearance of the leather and mechanical strength, are better or equal to those that of a traditionally prepared amino resin. Note de contenu : - EXPERIMENTAL PROCEDURE : Materials - Preparation of MG - Characterization of MG - FTIR analysis - APPLICATION PERFORMANCE OF MG : Physical and mechanical tests - Organoleptic properties - Colour differences - Shrinkage temperature determination - Free formaldehyde content in leather - RESULTS AND DISCUSSION : Orthogonal experimental results - FTIR analysis of MG resin - Application experiments of MG (trial 1) - COMPARISON WITH COMMERCIAL AMINO RESIN : Comparison of organoleptic properties - Comparison of physical and mechanical properties - Comparison of chemical indexes of leather and spent liquor - Comparison of dyeing properties En ligne : https://drive.google.com/file/d/1zoUkMI38NeJsf4Tz9PVrvw1r38ou6drW/view?usp=drive [...] Format de la ressource électronique : Pdf Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=21010 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
16162	-	Périodique	Bibliothèque principale	Documentaires	Disponible

Synthesis of orthanilic acid modified glyoxylated melamine resin with improved retanning and thermal properties / Muhammad Naveed Ashraf 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. 142-149 Titre : Synthesis of orthanilic acid modified glyoxylated melamine resin with improved retanning and thermal properties Type de document : texte imprimé Auteurs : Muhammad Naveed Ashraf, Auteur ; Shahzad Mehmood Khan, Auteur ; Shahid Munir, Auteur ; Rashid Saleem, Auteur Année de publication : 2019 Article en page(s) : p. 142-149 Note générale : Bibliogr. Langues : Anglais (eng) Catégories : Agents de tannage Cuirs et peaux -- Analyse Cuirs et peaux -- Propriétés mécaniques Cuirs et peaux -- Propriétés organoleptiques Mélamine glyoxal Polymères -- Synthèse Retannage Rhéologie Index. décimale : 675.2 Préparation du cuir naturel. Tannage Résumé : Amino resins have found important uses in leather manufacturing due to their selective filling properties. Conventional amino resins are produced from formaldehyde and result in an increase of formaldehyde content in finished leather greater than the permitted limits. Due to strict legislations and restrictions regarding formaldehyde contents in leather goods there is a growing demand to produce formaldehyde-free leather. In this study formaldehyde-free resins with improved thermal stabilities were prepared using glyoxal as condensing agent and orthanilic acid (o-amino-benzene sulphonic acid) as a sulfonating agent. The glyoxal to melamine ratio (G/M) was varied from 2-6 and orthanilic acid to melamine ratio (ONA/M) was varied from 0.5-3 to produce aqueous solutions of the melamine resins. The viscosity trend in the series of resins was observed by varying the degree of sulfonation and varying the glyoxal/melamine ratio. Progress of reaction was monitored by FTIR spectrum through functional group region. Newly synthesised melamine resins (MGONA) were comparatively applied on leather as a retanning agent against a conventional melamine-formaldehyde resin and further evaluated for tear strength, tensile strength and elongation at break. The leather retanned with the optimal resin was further assessed for organoleptic properties and SEM analysis. The thermal stability of the optimised resin was also evaluated comparatively against a conventional resin. The optimised polymeric resin was free from formaldehyde plus having better retanning properties and improved thermal stability. Note de contenu : - EXPERIMENTAL PROCEDURE : Chemicals and apparatus - Synthesis of glyoxylated melamine resins using orthanilc acid as sulfonating agent - RESULTS AND DISCUSSION : Schematic route - Rheology of resins - Application of MGONA resins as retanning agent - Quantitative free formaldehyde contents in leather - Mechanical characteristics of retanned leather - Organoleptic properties - SEM analysis (JEOL 6490) - Thermogravimetric analysis - Structural elucidation - Table 1 : Mole ratio and physical characteristics of synthesised MGONA resins - Table 2 : Leather processing conditions - Table 3 : Physical properties of leather after retanning process Permalink : https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=32671 [article]

Réservation

Réserver ce document

Exemplaires (1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
20989	-	Périodique	Bibliothèque principale	Documentaires	Disponible

---

1 (1 - 3 / 3)